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MIDDLE ALBIAN STRATIGRAPHY 

IN THE 
ANGLO-PARIS BASIN 



H. G. OWEN 



BULLETIN OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 
GEOLOGY Supplement 8 

LONDON: 1971 



MIDDLE ALBIAN STRATIGRAPHY 

IN THE 

ANGLO-PARIS BASIN 




BY 



HUGH GWYN OWEN 



Xi 



3 Plates, 52 Text-figures 



BULLETIN OF 

THE BRITISH MUSEUM (NATURAL HISTORY) 

GEOLOGY Supplement 8 

LONDON : 1971 



THE BULLETIN OF THE BRITISH MUSEUM 

(natural history), instituted in 1949, is 
issued in five series corresponding to the Departments 
of the Museum, and an Historical series. 

Parts will appear at irregular intervals as they become 
ready. Volumes will contain about three or four 
hundred pages, and will not necessarily be completed 
within one calendar year. 

In 1965 a separate supplementary series of longer 
papers was instituted, numbered serially for each 
Department. 

This paper is Supplement No. 8 of the Geological 
(Palaeontological) series. The abbreviated titles of 
periodicals cited follow those of the World List of 
Scientific Periodicals. 



Trustees of the British Museum (Natural History), 1971 



World List abbreviation 
Bull. Br. Mus. nat. Hist. (Geol. 



trustees of 
the british museum (natural history) 

Issued 19 January, 197 1 Price £6 



MIDDLE ALBIAN STRATIGRAPHY 

IN THE 

ANGLO-PARIS BASIN 

By H. G. OWEN 



CONTENTS 

I. Introduction ..... 
II. Acknowledgements .... 
III. Description and correlation of sections 

A. Weald ..... 
(i) Folkestone .... 

(ii) Folkestone to the Medway . 
(iii) Medway to Trottiscliffe 

(a) Paddlesworth T* 

(b) Trottiscliffe 
(iv) Sevenoaks area 

(a) Sevenoaks Brick Works Ltd 

(b) St. John's Brickyard 

(c) Dunton Green 

(d) Brasted 
(v) Brasted to Buckland 

(a) Westerham 

(b) Tandridge . 

(c) Buckland . 
(vi) Buckland to Upper Beeding 

(vii) Upper Beeding 
(viii) Hassocks to Eastbourne 

B. Isle of Wight, Dorset Coast 
(i) Isle of Wight 

(a) Redcliff 

(b) Rookley 

(c) Compton Bay 

(d) Ventnor to Niton 

(e) Blackgang . 
(ii) Ballard Cliff to Osmington . 

(iii) Thorncombe Beacon to Black Ven 
(iv) Conclusions ..... 

C. The outcrop from Devon to Bedfordshire 
(i) Okeford Fitzpaine (Dorset) 

(ii) Vale of Wardour to Devizes (Wiltshire) 

(a) Vale of Wardour 

(b) Maiden Bradley to Devizes 

(c) Caen Hill, Devizes 
(iii) Devizes to Thame (Oxon) 

(a) Badbury Wick (Wiltshire) 

(b) Badbury to Thame 



Page 
6 
8 

9 
ii 
ii 
15 
19 
19 

20 
23 
23 
26 
26 
28 
28 
28 

3i 

31 

33 
34 
41 
42 
42 
43 
43 
45 
45 
49 
49 
5i 
52 
52 
54 
57 
57 
57 
58 
61 
61 
61 



MIDDLE ALBIAN STRATIGRAPHY 



IV. 



(iv) Thame to Leighton-Buzzard (Bedfordshire) 

(a) Long Crendon (Bucks) 

(b) Haddenham (Bucks) 

(c) Aylesbury (Bucks) 

(d) Aylesbury to Leighton Buzzard 

E. Borehole Evidence 
(i) Hampshire basin 

(a) Winchester district 

(b) Relationship of Winchester to Portsdown, the Weald 

and the Isle of Wight .... 

(ii) London Basin, East Anglia, and Kent 

(a) London Basin, S. Essex, and N. Kent 

(b) The area of the Kent Coalfield 

F. Selection of sections in France 
(i) Comparison between Wissant and Folkestone 

(ii) The outcrop from the River Ornain (Meuse) 
To the River Armance (Yonne 

(a) Revigny-sur-Ornain (Meuse) 

(b) Pargny-sur-Saulx (Marne) 

(c) Les Cotes Noires (Haute Marne) 

(d) Courcelles pres CleYey (Aube) 

(e) La Vendue Mignot (Aube) 

(f) St. Florentin area (Yonne) 

(g) Summary . 
(iii) Pays de Bray 

(a) Villers St. Barth61emy . 

(b) Forges-Les-Eaux, and St. Martin 
(iv) Comparison between the Pays de Caux and the 

ISLE-OF-WlGHT . 

(a) St. Jouin 

(b) Cauville 

(c) Octeville 

(d) Cap de la Heve 

(e) Summary, and comparison with the Isle-of-Wight 
Definition of the Middle Albian substage and its zonal 

scheme in the anglo-paris basin 

A. Historical background ..... 

B. The Zonal scheme of the Middle Albian in the Anglo 

Paris Basin ...... 

(i) Definition of the base of the Middle Albian 
(ii) The Subzonal sequence .... 

(a) Subzone of Hoplites (Isohoplites) eodentatus 

(b) Subzone of Lyelliceras lyelli .... 

(c) Subzone of Hoplites {Hoplites) spathi 

(d) Subzone of Anahoplites intermedins 

(e) Subzone of Dimorphoplites niobe 

(f) Subzone of Mojsisovicsia subdelaruei 

(g) Subzone of Euhoplites meandrinus 
(h) Subzone of Euhoplites nitidus 
(i) Subzone of A nahoplites daviesi 

(iii) The position of the Subzone of Dipoloceras crislatum 
(iv) The Zonal Grouping 

(a) The Zone of Hoplites (H.) dentatits 

(b) The Zone of Euhoplites loricatus 



64 
64 
64 

65 
68 
68 
69 
69 

70 
72 
72 

74 
80 
80 

85 
86 



9i 
93 
94 
97 
99 
99 
100 

101 
102 
102 

107 
107 
107 

no 
no 

118 
118 
119 
119 
119 
121 
122 

123 
123 
124 
124 

125 
126 
128 
128 
129 



IN THE ANGLO-PARIS BASIN 



V. 



(c) The Zone of Euhoplites lautus 
Links with other Faunal Provinces . 

A. The boundaries of the hoplitinid province 

B. Links with sequences of other countries 
(i) West Pakistan 

(ii) Tethyan belt 
(hi) Algeria 
(iv) Somalia . 
(v) Madagascar . 
(vi) South America 

(a) Colombia 

(b) Peru . 



(vii) 

(vih) 
(ix) 
(x) 



Texas 
Canada . 
Greenland 
Conclusion 



VI. 



VII. 



VIII. 



Conditions of deposition in England 

(a) The Margins of the depositional basin in England and 
Northern France 

(b) The Structural Controls on Deposition in Southern England 

(c) Source of Middle Albian Sediments 

(d) The cristatum Subzone disturbance 
Review of the Ammonite Fauna . 

A. Description of new species 

B. Stratigraphical list 
References ..... 



129 
130 
J 30 
133 
133 
133 
134 
134 
134 
134 
134 
135 
135 
137 
138 
138 
139 

140 
143 
147 
148 
149 
149 
152 
155 



SYNOPSIS 

Much new information on the stratigraphy of the Middle Albian substage gained from sections 
in England and France is recorded, and where possible previous knowledge is revised, sufficient 
to stabilize the Ammonite Zonal scheme in the Anglo-Paris Basin ; d'Orbigny's type area of the 
Stage. The succession in England is compared in detail with that of northern France by refer- 
ence to sections in the Pas de Calais, Meuse, Marne, Haute Marne, Aube, Yonne, Pays de Bray, 
and Pays de Caux, several misconceptions being eliminated. The ammonite zonal scheme is 
discussed in detail to provide the basis for international agreement of a zonal scheme for the 
faunal province, here termed the hoplitinid ammonite faunal province, of which the Anglo- 
Paris Basin is but a part. A brief review is made of the faunal links between the hoplitinid 
province, covering much of Europe, and neighbouring ammonite faunal provinces. These links 
occur essentially in the lyelli Subzone near the base of the Middle Albian, and in the cristatum 
Subzone at the base of the Upper Albian. The palaeogeographical implications of the distribu- 
tion of the faunal provinces are mentioned briefly. A study of the conditions of Middle Albian 
deposition in England shows that it tends to follow the pattern of Lower Albian and Aptian 
sedimentation in direct contrast to that of the Upper Albian where a different pattern pre- 
vailed. A review of the ammonite fauna terminates the work. 



R£SUM£ 

L'auteur presente des nouvelles informations sur la stratigraphie de l'Albien moyen de 
l'Angleterre et de la France, afin d'etablir le plan zonale des ammonites dans le bassin anglo- 
parisien, qui est la region typique de l'etage de d'Orbigny. Les couches de l'Angleterre sont 
compares en detail avec ceux-la de la France septentrionale. L'auteur donne tous les detail du 
plan zonale des ammonites, afin d'etablir une province faunistique des ammonites hoplitinid6s. 
L'auteur discute les liens faunistique entre la province des hoplitinides et les provinces faunisti- 
que avoisinantes des ammonites. Ces liens ont bien surtout dans la sous-zone de lyelli aupres 



6 MIDDLE ALBIAN STRATIGRAPHY 

de la base de l'Albien moyen, et la sous-zone de cristatum a la base de l'Albien superieur. Une 
6tude de la m6de de deposition de l'Albien moyen en Angleterre montre qu'elle imite la deposition 
de l'Albien infeYieur et Aptien, non pas celle-la de l'Albien superieur. L'auteur finit en passant 
en revue la faune des ammonites. 



I. INTRODUCTION 

The Albian Stage terminating the Lower Cretaceous has been divided into Lower, 
Middle, and Upper Substages. In England, the Lower Albian is represented within 
the top beds of the Lower Greensand and its junction with the overlying clays of the 
Gault ; the Middle Albian within the Gault, and by the Lower Gault where this 
division is recognisable ; and the Upper Albian by the Upper Gault and the contigu- 
ous Upper Greensand. Both the Middle and Upper Albian are represented within 
the Red Chalk facies. In northern France and the Paris Basin there is a similar 
lithological sequence, excluding a Red Chalk facies but including local lithological 
units in various areas such as the Sables de Puisaye flanking the northern area of the 
Massif of Morvan. This essentially common sequence reflects the closely comparable 
depositional environment which existed in the area of the Anglo-Paris Basin during 
Albian times. 

This Basin extended from the area of the Massif Central and the Vosges in the 
south to the English Midlands (text-fig. 51). It was flanked on the west by the 
Variscan massifs of Armorica and Cornubia, and on the east and north east by those 
of the Rhine State Mountains and the Ardennes. Late Jurassic — early Cretaceous 
deformation provided the basic structural pattern for Lower Cretaceous sedi- 
mentation which achieved its greatest geographical extent during Albian times. 
Middle Albian sedimentation followed this earlier pattern, but this changed in the 
Upper Albian due to tectonic disturbances at its start. The Basin was linked with 
the surrounding shelf seas north of the Ardennes, and with Tethys by means of the 
Morvano- Vosges strait. These sea-ways provided important migration routes for 
the fauna. 

In terms of absolute radiometric dates, the Albian is taken by Casey (1964 ; 199) 
to commence at 106 my B.P., and is considered to have had a duration of 6 million 
years. However, as that author clearly states, this is purely an arbitrary figure, the 
Cretaceous being divided into twelve equal time units corresponding to the twelve 
Stages. At present, therefore, there is no alternative but to use the relative units of 
time implied in the zonal schemes based on the faunal succession. Of these schemes, 
that based on the ammonites is the one which has been most thoroughly investigated, 
and the one that has led to much difference of opinion both national and international. 
A good deal of this disagreement is due to insufficient knowledge of the succession, 
despite the considerable number of papers which have been published. 

Within the lengthy bibliography on the English Albian two major works stand 
out ; the Memoir by Jukes-Browne (1900), and the Monograph by Spath on the 
Albian Ammonoidea (1923-43). The work carried out before 1900 in certain cases 
was truly excellent. For example, that of De Ranee (1868) and Price (1879, 1880) 
at Folkestone, Newton (1897) at Okeford Fitzpaine, Dorset, and Keeping (1868) at 
Upware, Cambridgeshire. All this earlier work is ably summarised by Price and 



IN THE ANGLO-PARIS BASIN 7 

Jukes-Browne and it is unnecessary to repeat it here. Jukes-Browne's memoir 
included almost all the stratigraphical information then available obtained either by 
earlier workers, or by himself and William Hill for the Geological Survey. He 
provided a good picture of the stratigraphy of the Albian in England, and extended 
his study to make a brief examination of the Paris Basin. The accuracy of some of 
his and Hill's field observations can still be demonstrated, and their reading of 
certain sections now long since vanished can be interpreted in the light of recent 
information with reasonable confidence. 

The first part of Spath's Monograph appeared twenty-three years after the publica- 
tion of Jukes-Browne's memoir, and it was completed over a period of twenty years. 
Its coverage was not complete, however, a fact which it is important to bear in mind. 
It consists of the description of ammonite faunas from the comparatively few localities 
that Spath himself collected from, or that were represented in museum collections 
upon which he largely worked. Other sections, although available during this 
period, were not apparently collected from by him and so, important parts of the 
ammonite fauna were not described. Nonetheless, this very important work pro- 
vided the basis and stimulus for the detailed stratigraphic work that was carried out 
during that period largely by officers of the Geological Survey, and the work that 
has been carried out since. The final part, published in 1943, contains a useful 
review of the stratigraphic work carried out in the period since 1900. Since the 
completion of his Monograph, a great deal of new information has been obtained 
about Albian sediments in England. Contributions to our knowledge have been 
made by a number of authors, particularly by Casey and C. W. & E. V. Wright. 
Their papers and many others are listed in the bibliography and are discussed in the 
appropriate part of the text. 

In France, before Jukes-Browne's Memoir was published, Charles Barrois wrote 
three important papers on the French Albian (1875a, 1875b, 1878) . These, in associa- 
tion with d'Orbigny's Paleontologie Frangaise, provided a good picture of the strati- 
graphy and fauna of the Albian deposits of the Paris Basin. Barrois followed 
Hebert (e.g. 1875a) and others in including sediments, now classified as Upper Albian, 
within the Cenomanian. It is significant to note that Barrois already appreciated 
the magnitude of the break in the succession between what we now consider to be 
Middle and Upper Albian deposits in areas of the Paris Basin some 50 years before 
Kitchin & Pringle (1922a) recognised it in England. In his papers Barrois incorpor- 
ated the results gained by earlier workers such as Michelin, Leymerie, Raulin, Buvig- 
nier, Cornuel, Ebray, Hebert, Delatour, and others, and a comprehensive biblio- 
graphy is given by him (1878 ; 230-238). English workers such as Hopkins (1845), 
Topley (1868), Jukes-Browne & Hill (1896) and Jukes-Browne (1900) carried their 
researches into France, the latter authors providing new information particularly 
about the sequence in Normandy described previously by Lennier (1867). 

Much useful information was published in the period of 30 years which separated 
Barrois' work from the publication of an important thesis by Jacob (1908). This 
thesis greatly increased our knowledge of the Aptian and Albian stratigraphy of the 
French Alpine area and adjacent Switzerland, the site of the Morvano-Vosges strait. 
In the following two decades, however, only a few papers were published. Of these, 



8 MIDDLE ALBIAN STRATIGRAPHY 

Lemoine (1910) on the Yonne, Aube, and Haute-Marne, Ciry (1927) on the Cote d'Or, 
and Stieler (1922) on the coastal sections at Petit Blanc Nez, may be mentioned. In 
the period from 1930 until the war interrupted work, much new information was 
contributed by authors such as Breistroffer working in the French Alps (1931, 1933, 
1936, 1940), P. & J-P. Destombes at Wissant (1938a) and in the Pays de Bray (1938b), 
Larcher (1937), Houdard (1933, 1940) and Marie (1939, 1941a) working in the Aube, 
Yonne, Marne, and Haute-Marne. Marie's work on the Albian foraminifera and 
their zonal value included studies of sequences in the Pays de Bray (1941b) and 
Wissant (1941c). 

After the war, and with Spath's Monograph completed, Breistroffer (1947) 
presented an important discussion of the ammonite zones of the Albian in France 
and England. Since then papers on various aspects of French Albian strati- 
graphy have been published. This more recent work is summarised, and much new 
information added, in the report of the Colloque sur le Cretace inferieur held at 
Lyon in 1963 (1965). 

Of necessity the foregoing review is very brief, and only the more important works 
have been mentioned including those which give comprehensive bibliographies of 
earlier work. However, the relevant papers on the Albian of the Anglo-Paris Basin 
are discussed at the appropriate place in the text. Recent papers published in 
France and England show that disagreement exists on various aspects of the zonal 
scheme, and even the litho-stratigraphy. This disagreement is both national and 
international ; a serious state of affairs rendering distant correlation difficult (e.g. 
Young 1966) . It is even more serious when one realises that here we are dealing with 
d'Orbigny's " type area " for the Albian Stage. 

An agreed zonal scheme can only be based on a detailed accurate account of the 
succession throughout a whole province, and inter-provincial correlation can only 
be accurately made once the stratigraphical successions are fully known. The 
object of the present work is to attempt to give this detailed information. Its 
presentation is the more urgent now that recent geophysical work indicates the 
closer proximity of Greenland, North America, and Europe in Albian times (e.g. 
Carey 1955, 1958, 1963, Bullard et al. 1965), and the need to be able to compare in 
detail sequences in these areas with that of our own. 

The first part of this work, therefore, consists of the description and correlation of 
sections in England and France, and this contains much new information. The 
sections are shown graphically for easy reference. This descriptive part is sub- 
divided into convenient geographical areas. The second part consists of a detailed 
discussion of the ammonite zonal scheme given in Table 1 (p. 10), preceded by an 
historical introduction. This is followed by a review of the links between the Euro- 
pean ammonite faunal province and other areas, and in turn by a discussion of the 
conditions of deposition in England. The work is terminated by a brief review of the 
ammonite fauna, with^descriptions of three new species of stratigraphic utility. 

II. ACKNOWLEDGEMENTS 

This paper is an abridged version of the thesis accepted for the Ph.D. degree of the 
University of London. It is a very great pleasure indeed to acknowledge the help 



IN THE ANGLO-PARIS BASIN g 

and support which has made the present work possible. In particular, I wish to 
thank the late Professor J. H. Taylor, and my supervisor Dr. J. M. Hancock for the 
considerable help and hospitality afforded to me as a research student at King's 
College, University of London. Without the facilities provided by the various brick, 
tile, and cement companies, by national, regional and local authorities, and by 
private landowners both in England and France, all mentioned in the text, it would 
have been impossible to carry out the work at all. 

The following organisations and members of them have aided the work and to these 
my thanks are due : my colleagues in the Department of Palaeontology, British 
Museum (Nat. Hist.), in particular, Dr. H. W. Ball (Keeper), Dr. E. I. White (former 
Keeper), Dr. M. K. Howarth and Mr. D. Phillips, Dr. R. P. S. Jefferies, Mr. H. A. 
Toombs ; the Director of the Institute of Geological Sciences Dr. K. C. Dunham, Dr. V. 
Wilson (Assistant Director), Mr. S. C. A. Holmes (District Geologist S.E. District), 
Mr. R. V. Melville (Chief Palaeontologist) and Dr. F. W. Anderson, Dr. D. A. Gray 
(Water Department), Mr. L. S. O. Morris (Boring Department), Dr. R. Casey, and the 
members of their staff for making available outcrop and borehole material ; the Gas 
Council, Mr. P. Hinde (Head Geologist), and the late Professor V. C. Illing for per- 
mission to examine the Winchester and Cliffe groups of borings ; the Board of 
Directors of British Petroleum Ltd., Dr. P. E. Kent (Chief Geologist) and Dr. A. J. 
Martin, for making available borehole material and information ; Mr. S. B. Thomas 
(Ministry of Transport, Channel Tunnel Division), M. R. Malcor (Channel Tunnel 
Study Group), Mr. E. W. Jaccomb Hood (Channel Tunnel Site Investigation), and 
Mr. D. J. Carter (Imperial College) ; Mr. A. G. Brighton, Sedgwick Museum ; Brig- 
adier G. Bomford, Mr. F. H. Edmunds, and Dr. W. J. Kennedy, Oxford University ; 
Miss J. Royston, Buckingham County Museum ; and Mr. H. J. Bick (Central Electric- 
ity Generating Board). It is a pleasure to thank Mr. C. W. Wright for the loan of 
specimens and information. 

My special thanks are due to Dr. P. Destombes for his hospitality, and introduction 
to sections in the Pays de Bray and in the Yonne and Aube. M. J. Fourcher (Rouen) 
provided access at very short notice to the Bucaille Collection. I am indebted also 
to Dr. J. A. Jeletsky of the Canadian Geological Survey and Dr. Keith Young of the 
University of Texas. 

I am particularly grateful for financial aid from the following authorities : the 
Godman Fund, the Educational Authority of the London Borough of Bromley, the 
Central Research Fund of the University of London, the G. W. Young Fund of the 
Geologists' Association, and my parents. I wish to thank my wife also for her help 
in various ways. 

III. DESCRIPTION AND CORRELATION OF SECTIONS 

A good deal of stratigraphic information can be displayed to advantage in the form 
of diagrams, and so all the lithological sections are presented as text-figures. 
Correlation charts, however, cannot provide the necessary accuracy when used alone, 
and require an accompanying text. Only the critical ammonites are mentioned in 
this section as a more detailed list and its stratigraphical distribution is given later. 
For ease of description the account is divided into convenient geographical areas to 



to MIDDLE ALBIAN STRATIGRAPHY 

which no structural significance should be attached : depositional controls on sedi- 
mentation will also be discussed later. The sections in the Weald are described first, 
then the Isle of Wight, Dorset coast, and the outcrop from Devon to the Leighton 
Buzzard area of Bedfordshire. The Albian sediments of the Leighton Buzzard area 
and of East Anglia are to be described elsewhere, but in no way do they affect the 
stabilising of the Albian Zonal scheme. Borehole evidence in southern England is 



Table i 

Ammonite zonal scheme of the Middle Albian adopted here and discussed in detail on pages 
118-130. 



Substage 

Upper 
Albian 

(part) 



Middle 
Albian 



Zone 

Mortoniceras inflatum (part) 

Euhoplites lautus 
Euhoplites loricatus {2) 

Hoplites (H.) dentatus 



Subzone 



\ 



Hysteroceras orbignyi 
I Diftoloceras cristatum < - l) 

{Anahoplites daviesi 
Euhoplites nitidus 

f Euhoplites meandrinus 
J Mojsisovicsia subdelaruei 
Dimorphoplites niobe 
Anahoplites inter medius 






f Hoplites (Hoplites) spathi 
J Lyelliceras lyelli (3) 
Hoplites (' Isohoplites ') 
eodentatus 

C Protohoplites puzosianus w 
< Otohoplites raulinianus 

(1) Formerly included in the lautus Zone sensu Spath (e.g. 1941 ; 668). 

(2) First recognised by Owen (1958 ; 162). 

(3) Approximately equivalent to the benettianus Subzone of Spath non De Ranee (1868). 

(4) In better developed sequences in France (Pays de Bray, Aube) , this index fossil does not range up 
to the base of the eodentatus Subzone. 



Lower 


" Douvilleiceras 


Albian 


mammillatum 


(part) 


(part) 



then considered before attention is turned to the Paris Basin. A detailed compar- 
ison is made between the sections at Folkestone and Wissant (Pas de Calais) . Selected 
sections in the Meuse, Marne, Haute Marne, Aube, Yonne, and in the Pays de Bray, 
are described followed by a comparison of sections in the Pays de Caux with the Isle 
of Wight. The ammonite zonal and subzonal scheme employed in this account is 
given in Table 1 above. 







ORTIAND BEDS 



ERIDGE CLAY 



C CORALUAN BEDS 



LONDON 



» CHELMSFORD 




/u-'U 



• TUNBRIDGE 1 



L ASHFOI 




/EASTBOURNE 



Fig. i. Sketch map of the Weald and adjacent areas showing positions of sections and boreholes discussed in the text. 



IN THE ANGLO-PARIS BASIN 



A. Weald 



The Gault describes a narrow outcrop at the foot of the Downs from Folkestone in 
the east, around the northern, western and southern borders of the Weald to reach 
the sea again at Eastbourne (text-fig. i). Deposits of Middle Albian age are present 
throughout and reach their greatest known thickness in Sussex. No section has yet 
provided a complete and relatively uncondensed sequence. Although the greatest 
degree of representation is to be found in the Folkestone area of Kent and between 
Steyning and Ringmer in Sussex, even at these localities condensation at certain 
horizons is very marked. Fortunately, further west in the northern Weald some 
condensed horizons are greatly expanded, but this is offset by truncation westwards 
of deposits of the higher subzones of the Middle Albian due to tectonic movements and 
associated erosion within the cristatum Subzone. 

(i) FOLKESTONE 

In response to the general north-easterly dip, the Gault appears above the Folke- 
stone Beds at the top of East Cliff, where it overlooks the harbour, and declines to the 
shore in East Wear Bay. Copt Point is the promontary at the NE. end of East Cliff 
at the entrance to East Wear Bay, and it was shortly after a substantial cliff-fall in 
1959 that the section given in text-fig. 2 was measured. By far the bulk of the 
fossils, for which the Folkestone Gault is famous, were collected from the foreshore 
exposures in East Wear Bay (East Weir Bay of early authors), but due to cliff and 
shore stabilising work carried out by British Railways, these sections are now hidden 
beneath beach-sand (see Bisson in Smart et al. 1966 ; 293-296). It is worth recording 
that in the period between 1948 and 1956 when remedial work obscured the sections, 
a large slice of Gault extending from the top of Bed III to the base of Bed X could be 
seen from the area now covered by the western half of the Toe-weighting to about 100 
yds west of it. This slice was not greatly disturbed within itself, but at the line shown 
by Bisson (Smart et al., 1966 ; fig. 17, p. 294) the dip was in the order of 70°-8o° 
landwards. 

The Folkestone Gault has attracted the attention of many workers because of the 
intrinsic beauty of its fossils. The early history of research is ably summarised by 
Price (1879, 1880) whose bed notation is still broadly used today. De Ranee (1868), 
however, was the first to divide the Gault into Lower and Upper Divisions and to 
subdivide them further into eleven Beds. Price (1874, 1875) accepted De Ranee's 
Upper and Lower Gault and also recognised eleven Beds but these did not coincide 
with those of De Ranee. De Ranee later (in Topley 1875 ; 146) accepted the bed 
notation of Price but they do not coincide lithologically. Jukes-Browne subse- 
quently modified Price's account, and it is his reading of the section which has been 
accepted by subsequent workers (1900 ; 69-83). Spath (1923-43) drew heavily on 
the well preserved ammonite fauna of this locality, and indeed, the degree of repre- 
sentation in his Monograph is largely a reflection of the high degree of representation 
within the section itself. Spath (1923a, b, c ; 1926b), like Jukes-Browne (1900 ; 45), 
expressed his zonal scheme for the Middle and Upper Albian essentially in terms of 
the lithological sequence at Folkestone. 



12 



MIDDLE ALBIAN STRATIGRAPHY 



Llthotogy 



nd many portly phosphatised fossils in grey cloy 



y 



"'y of ' 



lOtcramuj sulcatu 



phosphotic nodules in grey cloy- 



Grey cloy with she 
phosphoti c nodule 



tis- containing pyntised fossils and scattered 



tiled hght-grey clay with numerous dark grey burrows: occunng as 
egular lenticles in dark grey cloy. 



ottered brown phospna 



fragments of I 



(i) Seomof bivalves, port-phosphatisc d fossils, and buff phosphotic nodules, / 



$5L 



Fawn-grey clay with shell seams and part ly phosphat ! sed fossils. Occasional 
lenticles of ferruginous mcrlstone occur. 



(iv) Cloy like 1 1(1.) possing at the top by lenses into Bed HI. 



fiii) Seom of blockish phosphotic nodules in dark grey cloy. 



(ii ) Dark-grey clay, blc 
phosphatic npduli 



et.with seams of crushed shells and sea 



1 1) Scam of cruinedft. part phosphatised shell s and irregular phosphatic nodules. 



(vii) Dark-grey slightly silly shelly day. 



(vi)Gntty grey clay becoming more glaucomtic and gritty downwards; 

sparsely I ossilif erous and with occasional thin scorns of phosphatic 'clots 



(v) Lorge phosphatic nodules momly casts of ammonites in shejly giauco 
loam — 'dentatus nodule bed' 



(iv) Highly giouc 



few blockish phosphotic noduli 



(ni)Scottered spherical septorion phosphatic nodules. 



tand. 
subd. 



Ft Ins M 

- 10-11 

2 10 



6 7 

1-2 
A 

1 



1 3 

— 2 



4 



4 
4-7 

= f I 

- 1 o-i 



Fig. 2. Cliff section of Lower Gault a few yards NE of the sewer, Copt Point, Folkestone, 

Kent. 



IN THE ANGLO-PARIS BASIN 13 

Since Spath completed his Monograph, our knowledge of the Lower Gault at 
Folkestone has been increased by Casey (1950) and the author (Owen 1958 ; 1963a). 
Bisson (in Smart, Bisson & Worssam 1966 ; 56-58) has given an account of the 
section, but this is based essentially on Jukes-Browne. The revised section of the 
Lower Gault, given in part by me in 1963 (1963a ; 36-38) and in full in text-fig. 2, is 
the first new account since Price (1880). It is slightly thicker than that of Price, but 
this is probably due to his section being further out from the modern cliff-line, the 
seaward slope of the land at Copt Point producing a slightly thinner sequence due to 
creep at the cliff of Price's day. 

Casey (1950 ; 272-3) divided Bed I into four sub-divisions corresponding to (i) the 
' Sulphur Band ', (ii) the ' Greensand Seam ', (iiia) the dentatus nodule bed, and 
(iiib) the remainder of the clays. He classified the whole of the ' Greensand Seam ' 
with the inaequinodum Subzone, later (e.g. in Worssam et al. 1963 ; 59) replaced by 
the index Hoplites (Isohopiites) eodentatus. The dentatus nodule bed and the lower 
part of the overlying clays were, following Spath, classified with the spathi Subzone, 
and the upper part of Bed I with the intermedins Subzone. He concluded that the 
benettianus Subzone (i.e. the lyelli Subzone) was probably absent (see also in Worssam 
etal, 1963 ; 59). 

Subsequent work has shown that Casey's subdivisions are too broad and a more 
detailed notation is given by me (Owen 1963a ; 36-38, 49) and in text-fig. 2. 

Fossils are rare in the ' Greensand Seam '. The specimens of Hoplites (Isohopiites) 
in the Institute of Geological Sciences (GSM 83165-6 Spath Coll.) are angular frag- 
ments like the nodules of I(ii) which is here classified with the eodentatus Subzone. 
Bed I(iii) has not yielded fossils to me, but in I(iv) at a depth of 2 inches (0-05 m.) 
beneath the dentatus nodule bed, I have collected, apart from the specimen of 
Hoplites (H.) cf. baylei Spath figured by me (1963a ; 37, pi. 3, fig. 3), a fragment of 
Beudanticeras sp. indet. together with one specimen of Neohibolites minimus (Miller) 
and a few indigenous and very delicate bivalves. The association of Hoplites 
(Hoplites) and Beudanticeras indicates the lyelli Subzone. From a knowledge of the 
lyelli Subzone successions at Small Dole (p. 35), Swindon (p. 61) and the Aube (p. 91), 
the writer is firmly convinced that the specimens of Hoplites (H.) aff. benettianus 
which occur rarely in the spherical phosphatic nodules immediately beneath the 
dentatus nodule bed (Owen 1963a ; 37, pi. 3, figs, ia, b ; 2a, b) are of late lyelli Sub- 
zone age. The presence of this Subzone at Folkestone is not surprising because it is 
well represented in the Gault of the Guilford (Waldeshire) Colliery shaft (p. 76) about 
7 miles (11-25 km.) from Copt Point, and in the Aycliff boring (p. 78). 

The classification of the remainder of Bed I has been discussed by the writer 
already (Owen 1963a ; 37-38, 49), and it is only necessary to question one statement 
made by Casey (in Hancock 1965 ; 247) that Anahoplites intermedins comes in a foot 
or two above the spathi nodule bed as a minority element in a fauna still dominated 
by Hoplites. If this were the case, then the Folkestone section would be unique. 
Species of Hoplites (H.) occur crushed in Bed I (vi) up to a height of 3 feet 2 inches 
(0-96 m.) . Higher up, ammonites are absent or very rare until one reaches the base of 
I (vii), at which level Anahoplites intermedins appears. At Folkestone, as at most 
other localities in the Weald, there is a gap in the ammonite fauna between un- 



i 4 MIDDLE ALBIAN STRATIGRAPHY 

doubted deposits of spathi and intermedins Subzone age. There is no break apparent 
in sedimentation, but the only common fossils are large Inoceramus concentricus. At 
localities such as Petersfield (Sussex p. 34), Osmington (Dorset p. 51), Devizes (Wilt- 
shire p. 60), and to a point also in the southern part of the Paris Basin (pp. 88,93,97) this 
gap in the Weald sequence is filled. There is indeed the association of Anahoplites 
and Hopiites (H.) but the forms of Anahoplites are very distinct and include A . grims- 
dalei sp. nov. and A. osmingtonensis sp. nov. ; forerunners of the evolutus-intermedius- 
praecox group. Hopiites (H.) continues on into the intermedins Subzone but is a very 
subordinate element in the fauna. 

The classification of the remainder of the Lower Gault at Folkestone by Spath has 
seen only a few modifications (Owen 1958 : i960 ; 376-7). Spath pointed out (1926b ; 
421) that the divisions between Subzones do not always coincide with the junction 
between beds. The details of Bed I (vi-vii) given by the writer in 1958 were taken 
from what are now obviously disturbed sections, but were then the best available, 
and should be discounted. The account given in 1963 was taken from a perfect 
section. Bed I (vii) and the whole of Bed II up to a level 3 inches (0-70 m.) below 
its top, are classified with the intermedins Subzone. The bulk of the ammonites are 
crushed and consist essentially of species of Anahoplites such as A. intermedins, 
A. praecox, and A. mantelli. Partly phosphatised ammonites occur in Bed II (i) and 
pyritic specimens occur very sparingly among the numerous crushed fossils in II (ii) . 
The fauna of these three subdivisions is very uniform, but in II (iii) we see the intro- 
duction of a particularly coarse development of A. praecox, and in II (iv), where 
' solid ' pyritic fossils are more common, Euhoplites pricei Spath is a very character- 
istic form. 

Dimorphoplites niobe Spath, already present in the intermedins Subzone, becomes 
common in the shell seam about 3 inches (0-076 m.) below the base of Bed III at which 
level Anahoplites of the praecox-intermedius group quite suddenly ceases to be im- 
portant. D. niobe, together with A. planus and A. spiendens then characterises the 
whole of Bed III, within the upper 2 to 3 inches (0-051-0-076 m.) of which, part or 
wholly phosphatised fossils with the nacreous shell occur sparingly. Bed IV (i) does 
not mark a great break in the sequence although semi-derived phosphatic fragments 
of fossils do occur. D. niobe, A. planus and A. spiendens still occur but the fauna 
becomes more diversified and Mojsisovicsia subdelaruei M. remota and M. spinulosa 
(Spath) appear as infrequent but highly characteristic species. These species of 
Mojsisovicsia occur indigenous in both IV (i) and (ii) which are classified with the 
subdelaruei Subzone (Owen i960 ; 376). Bed IV (iii) marks a greater period of 
erosion and its characteristic ammonite fauna was listed by Owen (1958 ; 157). This 
bed, together with the basal 2 inches (0-051 m.) of Bed V which contains the same 
fauna is classified with the meandrinus Subzone. Casey {in Smart, Bisson & Wor- 
ssam 1966 ; 109) and in effect Milbourne {in Hancock 1965 ; 247) state that Euhoplites 
meandrinus Spath occurs outside Bed IV (iii) and the basal part of Bed V. However, 
the author has never seen a specimen, either in the field or in the collections, from any 
other bed. Spath's original (BMNH, C 32306) was a pyritic specimen, now decom- 
posed, which with very little doubt came from the basal part of Bed V, as Spath 
thought likely (1930b ; 271). 



SUBZONES 



SANDLING FOLKESTONi 




Subzonal correlation lines 
Lithological correlation lines 



Fig. 3. Correlation of sections in Kent and east Surrey. 



w, 


crista turn 




daviesi 


v, 


nitidus 










111 


nio b e 


II 
l(vll) 


intermedius 


(vl) 


spathi 




tvotli 


ti> 


POrientqttfS 



IN THE ANGLO-PARIS BASIN 15 

The sudden change from a deeply sulcate to a channelled venter in Euhopiites which 
occurs at a height of 2 inches (0-051 m.) up from the base of Bed V was taken by the 
writer to mark the base of the nitidus Subzone and the lautus Zone (Owen 1958 ; 
157-8, 162). There are a few scattered phosphatic nodules at this level and a small 
break in deposition is further suggested by the sequence at Ford Place, Trottiscliffe 
(p. 22). The remainder of Bed V together with Bed VI are classified with the nitidus 
Subzone and yield a typical fauna. Apart from the highly burrowed nature of the 
clay, Bed VI is also characterised by particularly tuberculate examples of Dimor- 
phoplites of the parkinsoni type. The lower part of Bed VII, previously classified 
with the daviesi Subzone, in fact still contains a nitidus Subzone fauna and must be 
classified with that Subzone (Owen i960 ; 376). Anahoplites daviesi does not appear 
in the sequence until a height of about 5 feet (1-524 m.) is reached, and this and 
closely related forms characterise the remainder of these clays of Bed VII which are 
classified with the daviesi Subzone. 

Bed VIII at the summit of the Lower Gault was classified by Spath and subsequent 
authors with the cristatum Subzone here included in the Upper Albian (inflatum 
Zone). The depositional history of Bed VIII is complex. The lower nodule bed 
VIII (i) represents a moderate break in deposition, and its fauna includes the bivalves 
Inoceramus concentricus, I. sulcatus subsulcatus and /. sulcatus, and the ammonites 
Dipoloceras bouchardianum (d'Orbigny) and Beudanticeras beudanti (Brongniart) . 
At Wissant (p. 85) on the French coast 22 miles from Folkestone, the equivalent of 
Bed VIII (i) is represented by the clays of Bed 12 (v) in which a coarse form of /. 
concentricus at the base soon passes into the subsulcatus stage to achieve the sulcatus 
form at the top. This bed also yielded the holotype of D. bouchardianum and B. 
beudanti also occurs. It is, however, apparent that some material of late daviesi 
Subzone age is also present in the remanie fauna of Bed VIII (i) at Folkestone. This 
element can be demonstrated by the occurrence of very coarse developments of 
Anahoplites of the daviesi group and typical /. concentricus. 

A detailed discussion of Bed VIII and its fauna is out of place here but it is 
essentially of cristatum Subzone age. The uncondensed sequence at Wissant indicates 
that the incoming of the typical fauna of the cristatum Subzone was quite rapid. This 
fauna continues on into the basal few feet of Bed IX which will also have to be 
classified with the cristatum Subzone. Bed VIII is in all truth a junction bed as the 
early workers recognised. 

(ii) FOLKESTONE TO THE MEDWAY 

No complete sequence in the Lower Gault has been seen between Folkestone and 
Chrismill Lane, Thurnham, on the Maidstone By-Pass, a distance of 29 miles (46 67 
km.). What little information is available is ably presented by Smart, Bisson & 
Worssam 1966 (Folkestone to Westwell), Worssam et al., 1963 (to a few miles W. of 
Maidstone), and Dines, Holmes & Robbie 1954. A little additional information is 
given here, and the correlation of the sections is shown in text-fig. 3. 

It is apparent that the sequence seen at Copt Point has changed already by 
Elenden Gardens, Cheriton (Spath 1923c ; 141-2) but unfortunately no precise 



16 



MIDDLE ALBIAN STRATIGRAPHY 



details of this section were recorded. Bisson in Smart et al. (1966 ; 100) has described 
the Folkestone Brickworks section at Cheriton (TR 205376) in which I suspect that 
the lowest 2 feet 6 inches (0762 m.) recorded as 'Dark-grey slightly micaceous 
blocky clay with occasional phosphatic nodules ', underlying the basal cristatum 
nodule bed, is of daviesi Subzone age as at Copt Point, and at Wye near Ashford. 
However, I did not see this part of the succession. 

At Sandling Junction (text-fig. 4) the fauna of Bed 9 classified with the spathi 
Subzone is identical to that of Division A in the Maidstone By-Pass (Owen i960 ; 
372), and so, the age of the dentatus nodule bed has already changed at the outcrop 
within 5 miles (8-05 km.) of Copt Point (Owen 1963a; 49-50). No fossils have yet 
been found in the underlying glauconitic loams of Beds 4-8. Bed 8 (of Worssam 
1966 ; 99) at File's pit in Swan Lane, Sellindge (TR 11853915) is the equivalent of 
Bed 9 at Sandling, and Bed 6 yielded the specimen of Hoplites ? recorded by Worssam. 



Bed 



10 



Litholoq y 



Weathered grey clay. 



Phosphatic nodules mainly fragmentary cast s of Hoplite s (H.).^ 



' s. 



Grey slightly glauconitic clay. 



Scattered phosphatic nodules in qrgy slightly qlauconi tic clay. 



Mottled yellow, green, grey, glauconlt ic loam becoming more' c 
argillaceous upwards. j "J 



Shattered ferruginous phosphatic nodules 



Mottled glauconitic loa 



ith occasional phosphatic nodules. 



Shattered ferruginous phosphatic nodules in grey loor 



Dense band of phosphatic nodules in lenticular cemented gr 



Yellowish sand with small scattered phosphatic nodules 





Ft InsM 

6 

- 1 

1 
1 1 

1 6 

- 3 - 

- 4 

3-6 

6-9 
— 






• 


• • • ••• 


4£&£fe« 



Fig. 4. Section in Gault-Lower Greensand junction beds at Folkestone Quarries Ltd's 
Sandling Sandpit, c. 150 yds. NW. of Sandling Junction railway station, Saltwood, Kent 
(TR 14703690). 



This specimen (GSM., CW 855) is a definite Hoplites (H.) but there is no other 
indication of the age of the sediments overlying the puzosianus Subzone sediments. 
The principle bed of phosphatic nodules in the spathi Subzone sediments at the 
Granary Court Sand pit at Brabourne (TR 09004005) is also on the same horizon as 
that of Bed 9 at Sandling. At Brabourne, in the area where Hill (in Jukes-Browne 
1900 ; 84) records a section, the former Ashford & Naccolt Brick, Tile & Potteries 
Ltd., dug shallow pits in higher beds of the Lower Gault about 800 yards (731 m.) a 
little north of west from Park Farm (TR 08904065). About 8 feet (2-43 m.) of 
weathered brownish clay streaked with ferruginous matter was to be seen beneath 
superficial deposits. Towards the top of the clays a disturbed seam containing 
phosphatic nodules yielded fragments of the following : — 

Anahoplites planus (Mantell), A. pleurophorus Spath, Dimorphoplites aff. niobe, 
D. cf. doris Spath, Enhoplites cf. subtuberculatus Spath late mutation, E. microceras 



IN THE ANGLO-PARIS BASIN 



17 



Spath late mutation, Hamites tenuicostatus Spath, Inoceramus concentricus Parkin- 



son. 



The assemblage indicates the subdelaruei Subzone as restricted here and by the 
writer in i960, which coincides with the term ' lower subdelaruei Subzone ' given by 
Smart (in Smart, Bisson & Worssam 1966 ; 98). The age of the underlying clay was 
not determinable, but the whole sequence is similar to that of the Maidstone By-Pass 
(text-fig. 3) . Smart records cristatum Subzone fossils from a similar shallow working 
300 yds (274 m.) to the NNW. 

In the Ashford Brickworks Ltd pit (formerly the Ashford & Naccolt Brick, Tile & 
Potteries Ltd) situated 700 yds NW. of Sillibourne Farm and about no yds ENE. of 
Blackwall Farm, Wye (TR 04954445) the upper beds of the Lower Gault have 
recently been exposed (text-fig. 5). This is the pit recorded by Cornes (in Dewey 
et al., 1925 ; 263-4) as ' New Nackholt ', and by Smart at TR 049445 (1966 ; 98). 



Bed 



LI thology 



Dense seo m of phosphatic nodules and phosphotic fragments of tossils 



(iv) Dark grey cloy shelly with part phosphatised fossils particularly in 1 
basal inch. 



(iij) Dark grey clay with few fossils and occasional scattered phosphatic 
nodules. 



(n) Bed of scattered brownish phosphotic nodules in dork grey cloy. 



(i) Dark gre y clay. 



seen to 











Ft 


Ins M 


E 

O 










1—i 

1-3 
10 


■«5 






- 


W * 


C=D 


C=3 


CD CD 


— 


1 


* 5 








1 


1 

1 

3 n 


i *■ . 





Fig. 5. Upper beds of Lower Gault at Naccolt Brick Works (Ashford Brickworks Ltd), 
700 yds NW. of Sillibourne Farm and c. noo yds ENE. of Blackwall Farm, Wye, Kent 
(TR 04954445). 



Anahoplites daviesi and A. daviesi ornata appear at a depth of 10 inches (0-254 m 
below bed 2, the cristatum nodule bed, and the remainder of the clay up to bed 2 is 
classified with the daviesi Subzone. Whether the lower part of the exposed clays 
of bed 1 is also of daviesi Subzone age is not certain. Only a single nodule bed 
(bed 2) here represents Bed VIII at Folkestone and its character and fauna is almost 
identical to that of Division D in the Maidstone By-Pass (Owen i960 ; 374). The 
section recorded by Hill (in Jukes-Browne 1900 ; 84) at Kennington, the ammonites 
from which were re-determined by Casey (in Smart et al., 1966 ; 97), apparently 
showed some Lower Gault, but it is at present impossible to interpret the sequence. 

Unfortunately the sections recorded between Wye and Hollingbourne are in- 
sufficient to determine the succession. The preservation of the ammonites from 
Westwell Leacon and Kennington preserved in the Institute of Geological Sciences 
suggests nodule beds about the same horizon as beds C (ii) and D in the Maidstone 
By-Pass. The pit at Eyhorne Street, Hollingbourne, described by Hill (in Jukes- 
Browne 1900 ; 85) was alleged to show beds spanning the Lower Gault-Upper Gault 
junction. However, Casey (in Worssam et al., 1963 ; 59) has re-determined the fossils 
collected from this pit and demonstrated that the section was wholly in the Lower 
Gault and that Hill's reading of it was incorrect. If one compares the section given 



i8 



MIDDLE ALBIAN STRATIGRAPHY 



Div. 



17 



LI t holog y 



Dense seam of blackish phosphatic nodules and fossils in 
bluish grey clay. Nodules tend to divide Into two seams. 



(ill) Bluish-grey clay becoming darker upwards, with brownish 
partings and pockets of limonite after pyrltlsed fossils. 
Occasional phosphatised fossils occur with the shell 
especially at a level 4 inches below the top. A scattered 
line of small buff phosphatic nodules occurs 5 Inches above 
the base. 



xt 



(II) Bed of chocolate-brown phosphatic nodules in dark fawnish/ 
grey cloy. / 



■V. 



r< 



(I) Darkish, rather fawn-grey clay about 1 foot in thickness 
with shell seams and scattered phosphatic nodules, 
underlain by dark-grey shelly clay passing down into 
light speckled fawn-blue-grey clay with sporadic 
lentlcles of ferruginous marly clay and marlstone near 
and at the base. 



(ill) Dark blue-grey clay with shell seams, lightening In 
colour towards the top. 



(il) seam of Irregular-shaped phosphatic nodules. 



(I) Grey slightly fawn clay with many shell seams and 
bands of burrowed clay passing down into three feet 
three inches of greenish grey clay becoming progressiv- 
ely darker and more glauconitic downwards The clay 
is blocky with yellowish partings and contains seams 
of scattered incipient buff phosphatic nodules at 
heights of 2 ■feet 8 I nches, 3 feet 9 inches, 4 feet 6 
Inches, 6 feet 3 inches and 8 feet 8 inches. 



Bed of blackish phosphatic nodules, some septarian, In hlqhly\ 
glauconitic clay with some crushed fossils. _____ 



Glauconitic sandy clay, becoming sandier below. 



! 

6 
subd. 



I*. 



< J ? S ' " <— c__ 



»«flAW 



--..*-.--■ 



Ft Ins M 

- 3-4 



8 



4 



1-2 7- 



13 



Fig. 6. Lower Gault sections at NW. quadrant of A 249 clover leaf, Maidstone By-Pass 
(East Section) M 20, extending from a point 585 yds NE. of the Chiltern Hundreds public 
house to the A 249, Boxley, Kent (TQ 77805745). 



IN THE ANGLO-PARIS BASIN 19 

by Hill with that of the Maidstone By-Pass (Owen i960 ; 369-371 and text-fig. 6 
herein) it can be seen that the sequence exposed at Eyhorne Street included parts of 
the equivalent of Divisions B and C which appear to be identical to that of the By- 
Pass. 

There is nothing further to add to my account of the sections exposed during the 
construction of the Maidstone By-Pass motorway (M20) (Owen 1960), except for an 
unfortunate omission of a complete sentence in my reply to the discussion of my 
paper by Gray (1962 ; 469). The missing sentence read, ' As seen in the sections, the 
Tertiary faulting affects the beds [in the A 249 clover-leaf] in the following manner.' 
Without this sentence there is the implication that the faulting is intra-Albian which 
it certainly is not. The correlation of the sections is shown in text-fig. 3, and it can 
be seen that the stratigraphical succession is very uniform. 



(iii) MEDWAY TO TROTTISCLIFFE 
(a) Paddlesworth 

West of the Medway, the outcrop changes direction through an arc of about 12 but 
no complete sequence is seen until one reaches the Ford Place clay-pit, Trottiscliffe, 
where the Middle Albian sequence is thicker than at the Maidstone By-Pass. How- 
ever, in the early months of 1968 the Associated Portland Cement Manufacturers 
clay pit at Paddlesworth, which has for many years shown an important Upper 
Gault sequence, was cut further south exposing the higher part of the Lower Gault. 
The Middle Albian sequence is shown in text-fig. 7, and its correlation with the 
Maidstone By-Pass and Ford Place in text-fig. 3. The basic similarity with the 
sequence at Ford Place from the middle of Division 4 permits the use of the same 
divisional enumeration. 

By analogy with Ford Place, the 3 feet 6 inches (1-067 m -) °f clays at the top of 
Division 4 at Paddlesworth are almost certainly of subdelaruei Subzone age. They 
contain numerous Inoceramus concentricus and Hamites tenuicostatus as at Ford 
Place, but no specimens of Mojsisovicsia are yet to hand. These clays represent an 
expansion of nodule bed C (ii) at the Maidstone By-Pass. Bed 5 (i) contains a 
typical meandrinus Subzone fauna and the sediments up to the top of 5 (vii) are also 
classified with this Subzone. 5 (i) corresponds exactly to 5 (i) at Ford Place but does 
not contain phosphatised fossils with the shell preserved as at the latter locality. 
5 (ii-vi) correspond to 5 (ii-iv) at Ford Place and 5 (vii) is the direct equivalent of 
5 (v). In general the sequence is slightly thinner at Paddlesworth than at Ford 
Place, but it is much thicker than that seen at the Maidstone By-Pass where the 
equivalent sediments are but 2 feet 7 inches (0787 m.) thick. 

The sediments of lautus-Zone age at Paddlesworth 5 (viii) are 2 inches (0-051 m.) 
thicker than at Ford Place 5 (vi), and 1 inch (0-025 m -) thinner than at the Maidstone 
By-Pass. Part phosphatised fossils occur at the base of 5 (viii) and the species of 
Euhoplites indicate the nitidus Subzone, although the commonest ammonite is 
Dimorphoplites biplicatus (Mantell). Crushed Anahoplites planus occur in the top 
few inches, and there are a few uncrushed Euhoplites truncatus in the uppermost inch. 



20 



MIDDLE ALBIAN STRATIGRAPHY 



Whether the daviesi Subzone is represented at this height is uncertain. Sediments 
of daviesi Subzone age are 4 inches (o-ioi m.) thick in the Maidstone By-Pass. 

The nodule bed Division 6 is of cristatum Subzone age, and it is interesting to note 
that there is a tendency for this bed to divide a little into two, a feature seen in 
Division D in Sections 2 and 4 of the Maidstone By-Pass (Owen i960 ; 371). There 
is no question of there being two distinct nodule beds, but the feature is of interest in 
connection with the tectonic disturbance and associated erosion of the upper surface 
of the Lower Gault in cristatum Subzone times (p. 72). 



Div. 
6 



Li thology 



Brownish phosphatic nodules tending to divide Into two concentrations 
oil In shelly medium-gray burrowed cloy. 



(vlii) Mid-grey shelly clay with fawn patches- some extensively 

burrowed; scattered phosphatic nodules and part phosphatlsed 
fossils at base. 



(vii) Highly burrowed light fawn-grey clay, shelly and with lenticles 
of marlstone at the base. 



vi) Mid-grey burrowed shelly clay 



n 



w 



Scam of scattered phosphatic nodulci~ 



(iv) Shelly mid- g rey clay. 

(Ill) Buffish phosphatic nodules in mid-grey clay. 



(li) Shelly mid grey clay with lighter patches. 



(i) Brown phosphatic nodules, mainly casts of fossils in shelly clay>^/|i 



Lightish fawn grey clay, shelly, becoming darker below and burrowed 




Ft Ins M. 



4-9 



1 

2-5 
2 

7 
1 

e 

1 



1- 



o-J 



Fig. 7. Section in Lower Gault at southern side of the Associated Portland Cement 
Manufacturers' Holborough clay pit, 880 yds SE. of Paddlesworth, Snodland, Kent 
(TQ 69156165). 



(b) Trottiscliffe 

The sequence exposed in the Rugby Portland Cement Co's Ford Place Clay pit 
extends from the middle of the Folkestone Beds up to the varicosum Subzone of the 
Upper Gault. The Middle Albian sediments are shown graphically in text-fig. 8. 
Casey (1959) has given a brief account of the whole section, and a detailed account of 
the Gault-Lower Greensand junction beds (1961a ; 545). The upper part of the 
junction beds and the Gault have been described by Milbourne (1963) but his account 
is inaccurate both in lithological detail and in its subzonal classification. The writer 
has described the sequence in the spathi Subzone (1963a ; 38), but in view of Mil- 
bourne's account of this section it is necessary to redescribe the sequence in the 
Lower Gault (text-fig. 8) . 

Bed 9 of Casey (1961a ; 545) was stated to have a thickness of 3 feet (0-914 m.) and 
by Milbourne (1963 ; 58) as 5 feet (1-524 m.) : it is capable of subdivision (text-fig. 8). 
Bed 9 (ii) has yielded pyritic Hoplites (H.) spp. and Beudanticeras sp. and I follow 
Milbourne in classifying this horizon with the lyelli Subzone. Whether the eodentatus 



IN THE ANGLO-PARIS BASIN 



L 1 1 h olog y 



Dense seam of phosphatic nodules and fossils in she l l y q rgy clay. 



(vl)Oark grey shelly ekiy with partly phosphatised and partly pyritised fossils. 



(v) Mottled Bed. Light fawn grey clay with numerous burrows of dark grey clayV 
A shell seam with scattered phosphatic nodules marks the base. Scattered 
small phos phatic nodules occu r at to p. 



(iv)Dark grey shelly clay. 



(iii)Shell sean 



ith scattered small phosphatic nodules. 



(il) Dark grey shelly clay, a little burrowed, with a (ew scattered small 
phosphatic nodules and some partly phosphatised fossils. 



(i) Bed of large Irregular phosphatic nodules and occasional part-phosphatisea> a 
in dark grey clay. s 



Fawn grey clay with shell seams and partly phosphatised fossils more 
ferruginous and marly at the base which is marked by lenticular developments 
of ferruginous martstone. 



(vi)Lightcr grey clay than below, and more marly, passing in the top few inches 
into Division 4. 



(v)lrregular lino of phosphatic nodules in dark grey clay. 



_/ 



(iv)Dark grey shelly clay. 



UN) Seam of scattered phosphatised ammonite body chambers. 



(ii) Darkish grey clay becoming 
in colour. 



reasingly shelly upwards, and lights 



0)Dark gritty greyclay 



iitish phosphate mcipientiy 



Seam of black phosphatic nodules and mainly fragmentary casts of ammonitesx. 

ond other fossils in gritty dark grey clay. 



(iit)Dark grey gritty clay 



nerous crushed fossils 



(i i) Bed of pale soft phosphatic nodules and part ly phosphatised HopOtes (H.) 



(i ) Dark grey gritt y clay. 



(Hi) Highly glauconltic green loam with scattered septarian phosphatic nodules. 



(ii) Highly glauconitic dark grey-green cloy with a few pyritic an 



(i) Highly glauconitic dark grey— green loam with patches of greyclay 

ill-graded and pebbly in basal 6 inches. Thin seams of scattered spherical 
septarian phosphatic nodules occur at 2 and 10 inches above the base 



Fig. 8. Section in Lower Gault at the Rugby Portland Cement Co. Ltd's Ford Road clay 
pit, 450 yds N. of Ford Place House, and c. 1100 yds SSW. of Trottiscliffe on W. side of 
Ford Road, Trottiscliffe, Kent (TQ 63605910). 



22 MIDDLE ALBIAN STRATIGRAPHY 

Subzone is represented in 9 (i), or whether 9 (iii) is of lyelli Subzone age, in the 
absence of fossils cannot be determined at present. The Lower Gault can be divided 
into six broad lithological divisions corresponding to those recognised by the 
author in the Sevenoaks area (1958 ; 152 and text-figs. 3, and 9 herein), and the 
correlation of these with Paddlesworth and the four divisions seen in the Maidstone 
By-Pass is shown in text-fig. 3. Division 1 (i) has not yielded fossils, but 1 (ii) to the 
top of 3 (i) are classified with the spathi Subzone. Division 1 (ii-iii) contain the same 
species of Hoplites (H.) that occur in the dentatus nodule bed at Folkestone. Division 

2 is the ' upper dentatus-spathi nodule bed ' and contains the same ammonites that 
were recorded by the writer from bed 4 in the Lower Gault of the Buckland Sand & 
Silica Co. pit (Owen 1958 ; 151). 

No ammonites have been obtained from Division 3 (i), but at the base of 3 (ii) 
crushed Anahopiites intermedins and A . praecox appear in the succession, marking the 
base of the intermedins Subzone sediments, and range up through the remainder of 
Division 3. The coarse development of A. praecox known to occur in Bed II (iii) at 
Folkestone is found in the condensed bed 3 (iii), and Euhoplites pricei ranges through 

3 (iv) to the base of Division 4 (Milbourne 1963 table 1). The lower 4 feet 2 inches 
(1-321 m.) of Division 4 contains crushed examples of Dimorphoplites niobe, and these 
sediments are classified with the niobe Subzone. As Milbourne has demonstrated, 
Mojsisovicsia subdelaruei and its contemporaries range throughout the remainder of 
Division 4. The meandrinus Subzone is represented within the sequence from 
Division 5 (i) to the top of 5 (v) . The clays of 5 (i) to 5 (iv) contain the same fauna as 
Bed IV (iii) and the basal 2 inches (0-151 m.) of Bed V at Folkestone (Owen 1958 ; 
157). However, 5 (v) was probably deposited at Trottiscliffe during a minor phase 
of non-deposition at Folkestone. The marked change in the ventral aspect of 
species of Euhoplites which occurs suddenly 2 inches (0-051 m.) above the base of 
Bed V at Folkestone is not so abrupt at Trottiscliffe. In Division 5 (v) the peripheral 
aspect is transitional from the sulcate to the channelled state. Nonetheless, the 
characteristic species are more closely allied to the meandrinus Subzone rather than 
the nitidus Subzone. 

Division 5 (vi) contains a typical nitidus Subzone fauna but at the top, immediately 
beneath the cristatum nodule bed (Division 6), there are to be found the occasional 
part-phosphatised examples of Anahopiites daviesi. Division 6 contains numerous 
usually fragmentary fossils in a matrix containing crushed or partly phosphatised 
fossils of cristatum Subzone age. There are well preserved phosphatised ammonites 
with the shell which are of daviesi or nitidus Subzone age which have just been caught 
up into the phosphatic debris of the nodule bed from the clays beneath. Nonetheless, 
the clay sediment of Division 6 is of cristatum Subzone age. The phosphatic debris 
contains ammonites indicating the daviesi Subzone, but essentially the cristatum 
Subzone. 

At Trottiscliffe, therefore, as at Paddlesworth at least in part, we see an expansion 
of the sequence found at the Maidstone By-Pass, but virtually all sediments of 
daviesi Subzone age have been removed by the cristatum Subzone transgression. This 
expansion of the sequence reaches its known maximum in this area at the Sevenoaks 
Brick Works Ltd's pit at Otford. 



IN THE ANGLO-PARIS BASIN 23 

Part of Division 5 and Division 6 were exposed during the excavation of the 
reservoir for the Mid Kent Water Board some 600 yds ENE. of the centre of the Ford 
Place Clay pit (TQ 64055920). The lower part of the Gault was also exposed in the 
now long-abandoned Pascall's pit at Wrotham (TQ 62155780) about 2100 yds SW. 
of the Ford Place Clay pit and was described very briefly by H. J. W. Brown (1924 ; 
79, 81). Nothing can be concluded from his account, but it is unlikely that the 
sequence has changed much from that at Trottiscliffe. 



(iv) SEVENOAKS AREA 

This area has been an important centre for the manufacture of bricks and tiles for 
over a century. Pits have been opened near Kemsing Station (H. J.W. Brown 1924 ; 
80), Greatness Lane, Otford (Austin Browne 1949 : Khan 1952 : Casey 1954a : 
Milbourne 1956, 1962, 1963 : Owen 1958, 1963a, b), St. John's, Sevenoaks (Jukes- 
Browne 1900 : H. J. W. Brown 1924), Dunton Green (C. W. Wright 1947 : Khan 
1952 : Casey 1954a : Owen 1958) and Chevening (Lobley 1880). These sections, with 
the exception of the last, together with borehole evidence has given a very good 
picture of the Lower Gault in this area. Brown (1924 ; 80) records the occurrence of 
the nodule bed (Division 6) at the top of the Lower Gault just N. of the railway line 
at Kemsing Station, but there is no other information available about the succession 
between Wrotham and Otford, a distance of 6| miles. Today, the only section 
available is that exposed in the Sevenoaks Brick Works Ltd., pit at Otford. 



(a) Sevenoaks Brick Works Ltd., Greatness 

The sequence in the Lower Gault at the Sevenoaks Brick Works Ltd pit at Great- 
ness Lane, Otford, is shown in text-fig. 9. It was first described by Khan who dis- 
cussed the foraminiferal sequence (1952), then in part by Casey (1954a) when 
describing the distribution of Falciferella. Milbourne has described the succession 
(1956, 1962) but his reading of it was questioned by the writer (1958, 1963a). The 
six broad lithological divisions seen at Ford Place reach their maximum development 
here (text-figs. 3 & 9). 

A combination of evidence provided by several boreholes together with surface 
mapping shows that the Gault-Lower Greensand Junction beds are over 13 feet 6 
inches (4-11 m.) thick at Greatness. Division 1 (i) apparently is the transitional bed 
linking the Junction beds with the Gault. The writer reported (1963a ; 39) that the 
clays of 1 (ii) to (iv) probably represent the upper part of the benettianus (i.e. lyelli) 
Subzone, and so the bulk of the Subzone is probably present in 1 (i) and, together with 
the eodentatus Subzone, in the sediments below. The species of Protanisoceras (P.) 
in 1 (ii-iv) include P. (P.) barrense (Buvignier) a characteristic lyelli Subzone am- 
monite. In comparison with Ford Place, it can be seen that clay sedimentation 
commenced earlier at Greatness. The spathi Subzone is represented by Divisions 
1 (v-vi), 2, and 3 (i-ii). Division 2 is the ' Upper dentatus-spathi nodule bed ' as at 
Ford Place, and so, the spathi sediments of Division 1 are slightly thicker at Great- 



24 



MIDDLE ALBIAN STRATIGRAPHY 



^ -e> fQwn">f) SjOJj with g 

\"y phosph 




>gy 



ng seml-derlved and Indigenous fossils*" 



Zone nodule bed') 



Ion lies 
ottled clay with ye 
t-phpsphctised 



t phospnotic nodules 



us balls alter pyrlti 



1 port-pMospno 



' ochreous balls afterpyrite, i 



(j ii > Mottled blue-grey ond 

iiU_Perjls_tbnt laarr. of scattered p 



phosphotic nodula 



h cloy 



;loy of 5<li1T 



t-phospha 1 1 jsd 



(I) Mottled blue-qrey and fownlsh clay becoming more fawn-grey towards the 
base which Is morked by small lenticular developments of highly ferruginous 
marly clay. Impersistont shell seams occur throughout. 



(ill) Dork slightly brown. sh-grey clay. 



(ll)Seam of scattered dork brown phosphotic nodules 



(i)Broad banded clays; 
with lenticular d«v< 
lower band which v. 



ing dark-grey clay and lighter grey marly. 
Of ferruginous marlstone especially in the 
veen tO and tB inches in thickness. 



nodules with i 



(v)Dork grey shelly clay. 



(iv)Seam of shel is w 
body chambers. 



II buff phosphatic 



ond phosphotised i 



(no DarK grey shel I y clay 
phosphat ic nodules. 



grey bonds alternating; scottered butt 



(il)Greenlsh glauconltlc clay. 



(I ) Dork grey shelly 



Dense seam of black phosphotic 
shel I, in dork grey she 1 1 y c lay 



odules ond casts of ammonites, often with the 



(vOShelly dark grey cloy with port phospatlsed fo 



i shell seam 10 inche 



tv) Shelly seam with phosphotic nodules and fossils. 



(Iv)Oork grey shelly clay. 



tlll)Shell seam with phosphatic nodules 



(Ii) Dark grey shelly clay. 



(i)Dork grey sparsely fosslllfe 
with patches of glauconite 



ay becoming 
owest part e 



nzn> 



Ft ins M 

2-6 
3 
I 13— 



Fig. q. Lower Gault section at the Sevenoaks Brick Works Ltd's pit, 1300 yds NNE. of 
Bat & Ball railway station, 150 yds S. of the Otford-Kemsing railway line, and 150 yds W. 
of Greatness Lane, Otford, Kent (TQ 53605780). 



IN THE ANGLO-PARIS BASIN 25 

ness. Division 3 at both localities is closely comparable in thickness and character 
except at its base, where 3 (i) at Ford Place has become finer in character and shelly 
by Greatness and is represented in 3 (i-ii) . Ammonites that occur in 3 (i) at Great- 
ness consist almost exclusively of species of Hoplites {H.), the fauna being identical to 
that of the indigenous element of Division 2 itself which contains rarities such as 
Oxytropidoceras but no examples of Anahoplites were found by the writer. At Great- 
ness, 3 (ii) contains a few large Inoceramus concentricus but no ammonites. 

At the base of 3 (iii), Anahoplites intermedins and A. praecox appear in the sequence 
and this is taken by the author to mark the base of the intermedins Subzone. They 
range up to the top of Division 3 as at Ford Place. The thin seam of ' solid ' phos- 
phatised ammonite body chamber fragments containing the coarse form of A . praecox 
is also present at Greatness (3 iv), and above this Euhopiites pricei and its close 
relatives are characteristic as at Ford Place. Division 4 is thinner than at Ford 
Place, and only the basal 2 feet 2 inches (o-66 m.) can be classified with the niobe 
Subzone in contrast to the 4 feet 2 inches (1-27 m.) at Ford Place. At the level 2 feet 
2 inches (o-66 m.) above the base of Division 4 at Greatness there is a thin bedding 
plane (bed 10 of Milbourne 1956 ; 236) which contains species of Mojsisovicsia 
including M. subdelaruei (Spath). This marks the base of the subdelaruei Subzone 
which is here 8 feet 7 inches (2-616 m.) thick, and is, therefore, thicker than at Ford 
Place. M. remota (Spath) has been obtained from 4 (iii) ; and 5 (i) has yielded 
species of Dimorphoplites which indicate the subdelaruei Subzone rather than the 
meandrinus Subzone although Mojsisovicsia has not yet been found in it. It is 
important to note that lithologically the base of Division 5 at Ford Place does not 
correspond to the base of the same lithological Division at Greatness. The meandrinus 
Subzone commences with 5 (ii) which has yielded Euhopiites meandrinus Spath, E. 
aff. aspasia Spath, Dimorphoplites spp. and large partly crushed Anahoplites planus 
(Mantell) . No ammonites were recovered from 5 (iii) but the nodules of 5 (iv) have 
yielded fragmentary abraded Dimorphoplites and Euhopiites. At Greatness 5 (ii) to 
(iv) can be correlated with 5 (i) at Ford Place. Division 5 (v) to (vi) at Greatness 
also contains a meandrinus Subzone ammonite fauna, but 5 (vii) did not yield ammon- 
ites to me and probably represents 5 (v) at Ford Place which contains an ammonite 
fauna which shows some affinity with the nitidus Subzone above. 

The nitidus Subzone without doubt commences at the base of 5 (viii) at Greatness 
and includes 5 (ix) . Together they have yielded a typical nitidus Subzone fauna and 
measure 4 inches (0-102 m.) in thickness in comparison with the 1 foot 4 inches 
(0-406 m.) of 5 (vi) at Ford Place. Division 6, the ' lautus Zone nodule bed ', as the 
author demonstrated in 1958 contains a fauna including elements of the nitidus and 
daviesi Subzones as well as of cristatum Subzone age. Here, as at Ford Place, the age 
of the clay in which the phosphatic debris is embedded is of cristatum Subzone age. 

It is worth revising here the stratigraphical positions of the samples studied by 
Khan (1952) from the Sevenoaks Brick Works. 
Sample Si 5 ft 6 ins down from the top of Division 3 ; 

intermedins Subzone as Khan recorded. 

Sample S2 6 ins down from the top of Division 3 ; 

intermedins Subzone as Khan recorded. 



26 MIDDLE ALBIAN STRATIGRAPHY 

Sample S3 1 ft 6 ins below the top of Division 4 ; 

subdelaruei Subzone not niobe as recorded. 
Sample S4 6 ft below the top of Division 5 ; 

subdelaruei Subzone not niobe as recorded. 
Sample S5 4 ft below the top of Division 5 ; 

subdelaruei Subzone. 
Sample S6 2 ft below the top of Division 5 ; 

■meandrinus Subzone. 
Sample S7 2 ins below the top of Division 5 ; 

nitidus Subzone not subdelaruei Subzone as recorded. 
Sample S8 ' lautus-Zone nodule bed ' Division 6 ; 

cristatum Subzone. 

(b) St. John's Brickyard 

The brickpit owned by Durtnell and known in the literature as St. John's Brick- 
yard, or the 'Bat & Ball ' pit, is now overgrown. It was situated about 900 yards 
NNW. of the Bat & Ball railway station, 100 yds W. of Otford Road, Otford (TQ 
52805755), and 900 yds towards the WSW. of the Greatness pit. The section was 
first described by Hill (in Jukes-Browne 1900 ; 85) and additional information was 
given by H. J. W. Browne (1924) and by Spath (e.g. 1925 ; pi. XII, fig. 4). It 
showed a sequence (text-fig. 3) intermediate in thickness between that of the Great- 
ness pit and the Dunton Green section described next. 

(c) Dunton Green 

The Dunton Green Brick, Tile and Pottery Works Ltd pit was situated about 1650 
yds WSW. from the St. John's Brickyards. The section is now obliterated. It was 
first described in detail surprisingly late in its history by C. W. Wright (1947 ; 315-318) 
although it had been mentioned in the literature as early as 1880 (Lobley 1880). 
Spath recorded ammonites from it (1923-43) and Khan (1952) and I (1958) have 
referred to it briefly. Unfortunately, I saw only the sequence up to the basal part 
of Division 4, and the dotted portion in text-fig. 10 is taken from the account by 
Wright. 

Text-fig. 3 shows the extent to which the sequence is attenuated in comparison 
with that at Greatness to the ENE. and the Brasted borehole to the WSW. (not ESE. 
as given in Casey 1954 ; 266) discussed below. 

The exposed portion of Division 1 at Dunton Green was seen to be identical to the 
corresponding portion of Division 1 at Greatness. Division 2 contains the same 
fauna as at Greatness but the phosphatised material is devoid of the shell. Division 3 
(i) contains 'solid ' pyritised Hoplites (H.) with the nacreous shell, including H. (H.) 
dentatus densicostata Spath and H. (H.) escragnollensis Spath. This bed corresponds 
to 3 (i) at Greatness. The basal 2 feet 3 inches (o-686 m.) of 3 (ii) at Dunton Green 
consists of a glauconitic clay, immediately above which Anahoplites intermedius 
appears in the sequence and ranges up through the remainder of the Division. 
Although the sequence is much more condensed, the thin bed of phosphatised body 



IN THE ANGLO-PARIS BASIN 



27 



Oiv. 



LI thology 



1 8 I Bed of dark brown phosphatic nodule*. 
, T 



[Light! 



sh gray clay, slightly mottlad, darke 



ening below. 
Wright 1947;318j 



Lightish-somewhat fawn-grey clay. 



seen to 



(Iv) Dark-grey clay with small dark-brown phosphatic nodules. 



(Ill) Shell seam with phosphatlsed ammonite body chambers. 



(il) Dark grey clay with crushed fossils and scattered small 
phosphatic nodules passing down at the base into 
glauconltic gritty clay. 



( I ) Dark grey clay, shelly with some pyrltised ammonites. 
Dense seam of black phosphatic fragments of ammonites etc. 



Dark grey clay with crushed fossils chiefly ammonites. 



•%! *.'.•••. 



Ft Ins M. 
[- 3-4] 



7- 



[9 0] 



10 



6- 



5- 





1 4- 



3- 



2- 



1- 



6 
1-2 



0-1 



Fig. 10. Section in Lower Gault at the Dunton Green Brick, Tile & Pottery Works Ltd's 
pit, c. 550 yds S. of Dunton Green railway station on E. side of railway line, Longford, 
Dunton Green, Kent (TQ 515570). The dotted portion is completed from the account 
by Wright (1947). 



28 MIDDLE ALBIAN STRATIGRAPHY 

chambers of ammonites 3 (iii) occurs, and may be correlated with 3 (iv) at Greatness. 
3 (iii) at Dunton Green has yielded the coarse form of A . praecox figured by Spath 
(1925 ; 132, text-fig. 35e) according to its preservation. Only a foot of Division 4 
was seen clear by the writer, and for the remainder of the sequence Wright's account 
is available. 

(d) Brasted 

The Metropolitan Water Board well at Brasted has been described by Casey 
(1954a ; 266 : 1961a ; 544-5) and is displayed in text-fig. 11. Its relationship to the 
sections at Dunton Green and Squerryes is shown in text-fig. 3. The sequence in the 
higher part of the well is similar to that of Dunton Green and Greatness. Un- 
fortunately, the top of the Lower Gault bisects the ground surface further to the north 
of the site of the well, and the boring commenced at an unknown depth below the 
base of the Upper Gault. 

At a depth of 12 feet 6 inches (3-81 m.) the reddish burrowed marl suggests a 
correlation with the base of 5 (i) at Greatness. The only two ammonites preserved 
in the collection of the Institute of Geological Sciences (GSM) are Ca 339, Euhoplites 
sp. from a depth of about 8 feet (2-438 m.), of either subdelaruei or meandrinus Sub- 
zone age, in the preservation typical of the lower part of Division 5 at Greatness. The 
other, Ca 340 from a depth of 10 feet (3-048 m.), is of no diagnostic value. Together 
they neither confirm nor deny a subdelaruei Subzone age. The dividing line between 
Divisions 4 and 3 occurs between a depth of about 22 feet and 25 feet (6-706-7-62 m.) 
where the lithological change from fawn-grey clay to mid-grey clay occurs. The 
equivalent of 3 (iii) at Dunton Green occurs at a depth of 29 feet (8-839 m -) an d 
yielded Anahopiites praecox (GSM Ca 364-6) and Hoplites (H.) sp. (GSM Ca 367). At 
a height of 1 foot 6 inches (0-457 m -) above Division 2 a phosphatised fragment of a 
coarsely ribbed Anahopiites with the nacreous shell preserved was recovered. 

Division 2, the ' upper dentatus-spathi nodule bed ' was struck at a depth of 38 feet 
6 inches (9-296 m.). Below this level the sequence departs markedly from that of 
Dunton Green and Greatness. The 20 feet 6 inches (6-248 m.) of mid-grey clay below 
Division 2 contains Hoplites (H.) spp. throughout. No definite indication of the 
lyelli Subzone is seen, but a boring encompasses only a very small lateral area and the 
possibility that part of this succession is of lyelli Subzone age should not be dis- 
counted. There was also no evidence of the eodentatus Subzone although this may 
be present below 59 feet (17-983 m.) depth. 

(v) BRASTED TO BUCKLAND 

(a) Westerham 

The northern face of the Squerryes Estate Sand pit situated 2\ miles SW. of the 
Brasted Well was cut back in 1964 and provided the section given in text-fig. 12. The 
sequence of well-marked lithological divisions seen in the lower part of the Lower 
Gault in the Sevenoaks area, already indistinct at Brasted, becomes even less dis- 
tinct at Squerryes. Here, two clear-cut divisions are immediately apparent and 



IN THE ANGLO-PARIS BASIN 



29 



Dlv. 



L i thol og y 



Ft Ins M. 



Light grey weathered clay marked at the base by burrowed 
reddish marl. 



Fawn grey clay with phosphatic nodules. 



(Ill) Mid grey shelly clay. 



(II) Shall seam with phosphatlsed ammonite body chambers. 



(I) Mid grey shelly clay. 



Blackish phosphatic nodules and fragmentary fossils with the shell 



(v)Mid grey shelly clay. 



(iv)Phosphatlc fragments of fossils with the shell. 



(iii)Mld grey shelly clay with part-phosphatised, part-pyri t ised 
fossils. 



V 



\l/ 

I 
; l 
1 
I 
1 
1 



(i i) Phosphatic fragments of fossils with the shell in mid-grey clay. 



(i) Grey shel ly clay. 



I 

I 

I 

.M/ 



8 part iBIack sandy cloy with phosphatic nodules andiron pyrites. 
Remainder of Bed 8 of Casey 1961a;545. 



12 6 



15- 



7 



5 5 



10 



5 



Fig. 11. Vertical section of Middle Albian sediments in the Metropolitan Water Board 
well, 1000 feet NE. of St. Martins Church, to the E. of Station Road Brasted, Kent 
(TQ 47095574). 



3Q 



MIDDLE ALBIAN STRATIGRAPHY 



Dlv. 

& 

Bed 



Li thology 



14 



10 



(vilO Mottled blue-grey-fawn clay with crushed Ineceromus 

conctniriius and Hopli tts (H.) spp. with the shell. Seen to 



(vli) Blackish phosphatic nodules mainly casts of Hoptilts CWJwith^\ 
portions of shell s preserved, in shelly mottled clay. 



(vl) Clay as in 2(vlli)with partly phosphatised HoplHes (H.) 



(v) Clay as in 2 fl/lii) but much less fossiliferous. 



(iv) Shelly grey-blue-fawn clay with part-phosphatised part 
pyritised Hopliles (H.) 



(Hi) l.concenlricus shell seam with part-phosphatised fossils. J* 

(il) Shelly mottled blue-grey clay with crushed fossils. ^ * 

(I) Dense seam of small phosphotic nodules and phosphatised fossils !* 



(v) Mottled blue-grey-fawn clay with lenticles of ferruginous marl 



(iv) Clay as in 1 (v) but without phosphatic nodules, and with 
pockets of glauconitic quartz sand, and ferruginous 
lenticles. Crushed part-phosphatised Hopliies (H.) occur 
without the shell. 



(iii) Darker grey clay with ferruginous lenticles with 
indigenous part-phosphatised Hoptites IH.). 



(ii) Lighter grey clay with many ferruginous lenticles. 
Small phosphotic pieces with Hoplilts (H.). 



(i) Dark grey shaly mottled clay with reddish ferruginous 
lenticles. 



Dark grey gritty clay. 



Highly pyritic dark grey clay with greyish septarian phosphatic 
nodules pnd .part-phosphatised .fossils with.pynte replaced shells 
wealhermg fh ferruginous nchrenm lent i r-le*. „-»■" 



Dark grey pyritic clay, gritty, and weathering ferruginous. 



Dark qrey highly pyritic clay with septarian phosphatic nodules 
" \ weathering ferruginous./ 
Dark gritty grey clay with scattered septarian phosphatic nodules 



Seam of large spherical blackish phosphatic nodules in glauconiticlobrr 



Black gritty blocky weathering clay with glauconite. When 
weathered clay partings are coated with pyrite decompos- 
ition products. 



Bed 12 of Casey 1961a; 543 puiosianus Subzone 



»+•-****. 



E> 






Ft Ins M. 
9- 



1 11 



6- 



3- 



4-5 

7 



Fig. 12. Middle Albian sediments at the Squerryes Estates Sand Pits' pit, c. 150 yds N. of 
Covers Farm, Westerham, Kent (TQ 43305395). 



IN THE ANGLO-PARIS BASIN 31 

their correlation is shown in text -fig. 3. The sequence is, however, thinner than at 
Brasted. 

The 9 feet 2 inches (2794 m.) of Division 2, excluding bed (i), contains a typical 
spathi Subzone fauna, the ' upper dentatus-spathi nodule bed ' being represented in 
2 (vii). Bed (i) is the highest level in which Protanisoceras (P.) moreanum (Buvignier) 
occurs, and this is taken to mark the top of the lyelli Subzone sediments. The under- 
lying 11 feet (3-353 m.) of Division 1 represents the uppermost part of the lyelli 
Subzone as developed at Horton Hall, Sussex (p. 35). However, the typical develop- 
ment of this Subzone occurs within beds 13-15 of the Gault-Lower Greensand 
Junction. Bed 15 has yielded the following ammonites : 

Protanisoceras (P.) moreanum (Buvignier), Beudanticeras laevigatum (J. de C. 
Sowerby), B. sanctaecrucis (Bonarelli), B. albense Breistroffer, Hopiites (H.) dentatus 
(J. Sowerby), H. (H.) bullatus Spath, H. (H.) baylei Spath, Lyelliceras lyelli (d'Or- 
bigny), Brancoceras versicostatum (Michelin non d'Orbigny, nee Douville), ' Oxytropi- 
doceras ' cf. evansi (Spath). 

Bed 13 has yielded Beudanticeras laevigatum, Hopiites (H.) spp., ? Otohoplites sp. 
ind., Lyelliceras sp. Beds 10-12 contain Hopiites (1 sohoplites) spp., including H. (I.) 
eodentatus (Casey 1961a ; 543). 

(b) Tandridge 

The Coney Hill Sand-pit, Barrow Green (TQ 37755250), situated about 3^ miles 
WSW. from Squerryes, has already been described by the author (1963a ; 39). It is 
apparent that the sequence has become thinner (text-fig. 3). Between Tandridge 
and Buckland, a distance of 9 miles, there is no information concerning the sequence 
at the outcrop. 

(c) Buckland 

The Buckland Sand & Silica Co's pit at Buckland (TQ 231512) was described by 
the author in 1958 (1958 ; 149-152), however, a certain amount of revision is now 
necessary. The sequence (text-fig. 13) is not unlike that of Ford Place, a fact already 
recognised in the Gault-Lower Greensand Junction Beds by Casey (1961a ; 552). 
Whether the eodentatus and lyelli Subzones are present in the upper part of the 
Gault-Lower Greensand Junction as at Ford Place is at present unknown (p. 20). 
The spathi Subzone is represented within beds 2-6. Bed 2, tentatively classified 
with the benettianus Subzone in 1958, was later included in the spathi Subzone (Owen 
1963a ; 47-48). It contains the same ammonites as Division 1 (ii) at Ford Place. 
Bed 3 is the obvious correlative of 1 (iii), and Bed 4 is the equivalent of Division 2, 
the ' upper dentatus-spathi nodule bed '. Bed 4 has yielded the best preserved fauna 
yet known from this horizon, and the effect of strong erosive currents on the sea- 
bottom is demonstrated by the effaced nature of the upper surface of the nodules. 

Beds 5-1 1 probably represent Division 3 at Ford Place but the character of the clay 
is very different. In general the sediments are gritty clays with intercalated beds of 
ferruginous marlstone, and the fossils have shells replaced by pyrite. Beds 5 and 6 



32 



Bod 



MIDDLE ALBIAN STRATIGRAPHY 

Li thology 



10 



Mottled brown and blue-grey clay with selenite. A seam of crushed 
bivalves occurs at the base with poorly preserved part-phosphatised 
ammonite;. 



Light-grey weathered clay with much selenite. 



Very dark brown clay. 



Dark blue-black blocky clay with yellowish patches mainly on 
partings. 



Highly ferruginous yellow clay with stony lenticles of reddish marlst- 
one containing disc-shaped pebbles of micaceous morlstone. ^* 



Dark grey clay with pyritised and partly-phosphatised ammonites 
but usually crushed flat. 



Impersistent but wel I developed Ipnticlesof hard ferruginous ,. 
marlstone with lateral interstitial gritty c lay-marl. / 



Hard brownish marly clay with marly seams passing down into 
the bed below. 



Dark grey slightly mottled clay. 



Greyish-white to black phosphatic nodules, brownish when 
weathered, mainl y ammonite casts with abraded upper surfaces 



Dark grey clay with pockets of glauconite, some oxidised. 
Phosphatic nodules occur scattered at about the middle of the 
bed. 



Scattered subangular phosphatic nodules I n gritty glauconiticclay > \' 



Ft Ins M 



Gritty glauconitlc clay with patches of glauconite sand. 



urn ezzz; 






c2 

1-4 



Gault-Lower Greensand junction beds 



Fig. 13. Section of Lower Gault in the Buckland Sand & Silica Co's sandpit extending 
from a point 2100 yds WNW. of Reigate railway station to a position c. 250 yds SW. of 
Dowdes Farm, and 50 yds S. and roughly parallel to the Dorking-Redhill railway line, 
Buckland, Surrey (TQ 232512). 



Ft HASSOCKS HORTON HALL STORRINGTON PITSHA 



SELBORNE WRECCLESHAM SHERE 




BUCKLAND TANDRID&E 



^subfrtarw 




nl*b* 












7 






Subzonal coi 
Lithologlcal 



relation lines 
orralalion lin 



Fig. 14. Correlation of sections in Surrey, Hampshire, and Sussex, at the outcrop. 



IN THE ANGLO-PARIS BASIN 33 

are classified with the spathi Subzone, Beds 7-1 1 with the intermedins Subzone. The 
siltier nature of the sediments of the intermedins Subzone heralds the sequence seen 
further west at such localities as Winchester (p. 69) , Didcot (p. 63) , and Devizes (p. 60) . 
The niobe Subzone is probably present in the top of these sediments and possibly in 
the light grey clay of Bed 12 which can be correlated with the base of Division 4 at 
Ford Place. A re-examination of the ammonites from Bed 13 indicates that it 
should be classified with the subdelaruei Subzone as the writer considered possible in 
1958. 

The presence of higher Middle Albian subzones in the sequence is at present un- 
certain. Gossling (1929 ; 251) reported, from Spath's determinations of the am- 
monites found in the Merstham trench, that here the Upper Gault rests directly upon 
the dentatus Zone. However, Gossling did not give a detailed account of the succes- 
sion and, moreover, the trench was only 4 feet (1-219 m.) deep. In the Buckland 
Sand & Silica Co. pit large distorted blocks of pale-grey clay were seen in the super- 
ficial deposits. These blocks contain orbignyi Subzone fossils and the bed from which 
they were torn cannot be far to the northward. However, in the foundations of 
Wray Common County Primary School at the N. end of Kendal Close, Reigate 
(TQ 26975092), the ' lautus Zone nodule bed ' was located. The fauna obtained 
indicated that its character was closely comparable to that of Division 6 in the 
Sevenoaks area. 

(vi) BUCKLAND TO UPPER BEEDING (text-fig. 14) 

There is very little information available at the outcrop between Buckland and 
Shere, a distance of io| miles, except that given by Dines & Edmunds (1933). The 
sections exposed during the cutting of the Shere By- Pass road have been described 
by the writer (Owen 1963a). There is very little doubt that the outcrop here is 
affected by a strike fault with a substantial northerly throw as Kirkaldy concluded 
(1958 ; 18). The structure illustrated by the author (1963a ; 41, text-fig. 1), the 
greatly attenuated width of the outcrop, the far greater thickness of the Gault in the 
West Clandon Waterworks boring, and the sequence at Albury (Edmunds in Dines & 
Edmunds 1929 ; 41-2) all support the presence of such a fault. The true degree of 
representation in the Lower Gault in this area is, therefore, uncertain, and will not 
be determinable until a cored borehole is drilled to the north of the disturbed ground. 

The notable feature in the lower part of the Lower Gault between Shere and 
Shalford is the development of the eodentatus and lyelli Subzones (Owen 1963a, 
Wright & Wright 1948). Whether this development continues west to Whiteacre 
Copse on the Guildford-Godalming By-Pass road is unknown (Lea 1932 ; 320-1 ; 
Owen 1963a ; 50). There is a similar dearth of information further west. However 
in the Institute of Geological Sciences there is a small suite of specimens from the 
Gault exposed in a gravel pit off the Farnham to Runfold road at about 1 mile ENE. 
of Farnham and immediately W. of the railway bridge (SU 85854755) GSM. 
He 2337-45, which indicates the presence of lautus Zone sediments in this area. 

The sections at Wrecclesham, Selborne, and Nyewood, have all been described by 
the writer (Owen 1963a). Text-fig. 14 shows that the sequence in the spathi Subzone 



34 MIDDLE ALBIAN STRATIGRAPHY 

expands south of Wrecclesham to reach its greatest known thickness in this area at 
Selborne. It then thins southwards towards Nyewood, and between this locality 
and Storrington the Gault rests directly upon the oxidised indurated ' iron grit ' at 
the eroded top of the Folkestone Beds. How much more of the Middle Albian is 
represented in the higher beds of the Gault is uncertain. I expressed the qualified 
opinion (1963a ; 51) that at Selborne it appeared that the cristatum-orbignyi Subzone 
transgressions had cut down to the spathi Subzone, a view disputed by Milbourne (in 
Hancock 1965 ; 250). 

Osborne White (1910 ; 17) followed Jukes-Browne's interpretation of the ' inter- 
ruptus ' Zone (see p. 111). He records at Bradshott Hall (1910 ; 20) 2 feet (0-609 m -) 
of clay with phosphatised ' Hoplites interruptus ' separated by 3 feet (0-914 m.) of 
deposits from sediments containing Inoceramus sulcatus indicative of the lower part 
of the Upper Albian. Unfortunately, this material has not been traced. The lowest 
part of the intermedins Subzone with Anahoplites osmingtonensis no v. is present at 
the outcrop in the Petersfield area (e.g. BMNH, C 35482-3). Further information 
has been provided by borings carried out for the Gas Council by the British Petro- 
leum Co. in the Winchester area in the deeper part of the Wessex basin (p. 69). 
There, sediments of the intermedins Subzone are present above the spathi Subzone, 
and the orbignyi Subzone is also represented within the silty clay facies. 

Between Petersfield and Storrington only three sections are available, all in the 
spathi Subzone ; Nyewood, Pitsham, and Sullington (Owen 1963a). Recently, 
Mr. C. J. Wood of the Institute of Geological Sciences recognised in the Brydone 
Collection the material recorded by Jukes-Browne (1900 ; 112) from a well to the N. 
of Graffham village. The specimen recorded as Hamites punctatus ? is here referred 
to Protanisoceras (P.) barrense (Buvignier) and is preserved in lilac-grey silty clay, 
the shell originally having been replaced by pyrite. It is accompanied by Inoceramus 
concentricus in the same preservation. The ammonite indicates the lyelli Subzone. 
The specimen of Hamites attenuatus is indeed of that species, but is preserved in 
weathered yellowish pale-grey tough silt. It is of either loricatus or possibly lautus 
Zone age. 

Osborne White (1924 ; 26) described a well section examined by Templeman 
situated on the W. side of the lane to Barns Farm, 300 yds S. of its junction with the 
Washington-Storrington A283 road (TQ 10501345). Below 10 feet (3-048 m.) of 
clay containing an Upper Gault fauna, about 40 feet (12-192 m.) of Lower Gault was 
proved including the cristatum and the upper part of intermedins Subzones. In a well 
bored at Wiston Hall between Washington and Steyning 176 feet (53-644 m.) of 
Gault was proved (Osborne White 1924 ; 25). It seems likely, therefore, that in this 
area the succession in the post spathi Subzone sediments is closely comparable to that 
described below exposed in the Horton Clay pit. 

(vii) UPPER BEEDING 

The Lower Gault section exposed in the British Portland Cement Manufacturers 
Ltd's Horton Clay pit is shown in text-fig. 15, and its relationship to sections west and 
east is shown in text-fig. 14. The pre-war workings were described by Osborne White 



IN THE ANGLO-PARIS BASIN 35 

(1924 ; 27-8), and the current sections have been described in part by Milbourne 
(1961 ; 135-7), Casey (1961a ; 558), and Owen (1963a ; 46). It shows the thickest 
sequence yet known in the Lower Gault of England, and is undoubtedly the most 
important. The clays contain finely disseminated pyrite, and their silty nature 
allows the deep penetration of weathering agents ; this obscures the bedding for at 
least 12-14 feet (3-658-4-267 m.) from the surface, but fortunately there is a dip of 
8° S. present. In the fresh condition, the clays are seen to be fairly uniform through- 
out, and the Divisions adopted here are based upon cycles of sedimentation. Each 
cycle commences with relatively rapid sedimentation and terminates with partly 
arrested deposition indicated by marly seams and cementstone nodules. Individual 
units display an alternation of dark-grey and more fawn-grey bands. That this is an 
original feature is occasionally shown by the fauna ; there being often a more diverse 
benthos in the fawn-grey bands. 

Casey has described the boreholes drilled over the area of the northern field 
situated to the E. of Horton Wood (1961a ; 558). The subsequent excavation of this 
field commenced in 1964 at the northern boundary, and the sequence is now being cut 
down dip. There is unfortunately a small gap in the observed sequence as shown in 
text-fig. 14, between this new field and the older workings. 

Eodentatus & basal lyelli Subzones 

About 13 feet (3-962 m.) of glauconitic sandy clay and loam (1 (i) & (ii) ) classified 
with these Subzones occurs below the lowest level seen in the excavations (Casey 
1961a ; 558). 

lyelli Subzone 

Divisions 1 (ii) to the top of 2 (vi) are classified with this Subzone. As this is the 
first time that such a faunal sequence has been described in England, it is discussed 
in detail. The top 3 feet 8 inches (1-117 m -) °f x (^) * s seen m the excavations, but 
only the upper foot is fossiliferous and this has yielded Hoplites (H.) spp. and the 
ubiquitous Inoceramus concentricus, among other fossils. The shell seam that marks 
the base of 2 (i) has yielded the following : — 

Protanisoceras (Protanisoceras) nodoneum (Buvignier). P. (P.) barrense (Buvignier), 
P. (P.) alternotuberculatum (Leymerie), Beudanticeras laevigatum (J. de C. Sowerby), 
B. albense Breistroffer, Hoplites (H.) spp., Lyelliceras aff. lyelli (d'Orbigny), Branco- 
ceras (Brancoceras) sp., Neohibolites minimus (Miller), /. concentricus Parkinson, 
Acila (Truncacila) bivirgata (J. de C. Sowerby), Natica sp. 

A comparable fauna occurs throughout the remainder of 2 (i). In 2 (ii) the 
benthonic element of the fauna increases in importance and one of the characteristic 
fossils is a solitary caryophyUid coral. The ammonites consist essentially of species 
of Hoplites (H.) and Protanisoceras (P. barrense & P. nodoneum) ; Lyelliceras is not 
common. The benthonic element is much reduced and the nekton to a lesser extent 
in 2 (iii) . The ammonites include the following : 

H. (H.) dentatus (J. Sowerby), H. (H.) spp. common ; P. (P.) barrense, Lyelliceras 
lyelli (d'Orbigny) the lowest definite occurrence of the typical form, Beudanticeras 
sp., accompanied by I. concentricus. 



36 



MIDDLE ALBIAN STRATIGRAPHY 



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38 MIDDLE ALBIAN STRATIGRAPHY 

A much more diverse fauna appears in 2 (iv). A thin bedding plane 4 inches 
(o-ioi m.) above the base, sometimes washed out, has yielded one of the best pre- 
served ammonite faunas yet known from the lyelli Subzone. The fossils are part- 
phosphatised and part pyritised. Some ammonites are in a ' death rest ' position ; 
that is, they are vertically orientated resting on the venter. The amount of distortion 
permits the compaction ratio of the clay to be deduced. The fauna includes : 

P. (P.) nodoneum.P. (P.) barrense, Pseudhelicoceras argonnensis (Buvignier), P. sp., 
Beudanticeras laevigatum, B. albense Breistroffer, B. sanctaecrucis Bonarelli, Hoplites 
(H.) baylei Spath, Hoplites (H.) spp. Douvilleiceras sp. juv., Oxytropidoceras evansi 
(Spath), 0. sp., Lyelliceras lyelli (d'Orbigny), L. gevreyi (Jacob), L. sp., Brancoceras 
senequieri (d'Orbigny), B. versicostatum (Michelin non d'Orbigny nee Douville) B. 
spp., Inoceramus concentricus, Semisolarium moniliferum (Michelin). ' Auricula ' 
acuminata Deshayes. Hemiaster sp. 

This list shows a preponderance of lyelliceratid ammonites over the hoplitids which 
are greatly subordinate in actual numbers. The fossils are mainly crushed flat in the 
remainder of 2 (iv) and (v) but there is no significant difference in the fauna. Large 
uncrushed or partly crushed fossils occur in 2 (vi) and include : 

P. (P.) barrense, Beudanticeras sanctaecrucis, H. (H.) benettianus (J. Sowerby), H. 
(H.) spp., Lyelliceras lyelli, Brancoceras spp. Eutrephoceras sp. 

At this level Hoplites occurs in roughly equal numbers to the non-hoplitid genera 
combined. Some of the ammonites are also in a vertical 'death rest ' position and 
these, like those in 2 (iv), have a common orientation indicating a current direction 
coming from what is now 210 Magnetic. 

spathi Subzone 

Divisions 3 and 4 are classified with this Subzone. There is a sharp change in the 
ammonite fauna at the base of Division 3, the ammonites consisting essentially of 
Hoplites (H.) spp. At the commencement of the spathi Subzone, deposition of 
sediments increased rapidly and the bulk of the remainder of the Lower Gault, 
although very fossiliferous, yields little but crushed material except at a few horizons. 
Sedimentation during the spathi Subzone was particularly thick. At least 56 feet 9 
inches (19-812 m.) of clays have been observed and the gap in the sequence between 
the northern field and the main workings is probably only a few feet. 

Division 3 (i) contains numerous I. concentricus and crushed Hoplites (H.) the 
bulk of which possess dentatus-like ribbing : a few pyritic nuclei occur. Protanisoceras 
(P.) spp. have been obtained from Division 4 (i) but otherwise the heteromorph 
ammonites are almost exclusively species of Hamites. A beautifully-preserved 
fauna occurs in 3 (ii)-(iv) consisting mainly of ammonites and almost entirely of 
species of Hoplites (H.) identical to that of the well preserved element in the dentatus 
nodule bed at Folkestone (p. 13). Some specimens reach a diameter of 9 inches 
(0-228 m.). A loose block certainly from either 3 (ii) or (iv) contains an example of 
Mojsisovicsia delaruei (d'Orbigny). Division 4 (i) has a fauna closely comparable to 
that of 3 below. However 4 (ii) contains species of Hoplites (H). transitional from 
those seen below to those characteristic of the upper part of the spathi Subzone. 
They are of the grade well represented condensed in Division A of the Maidstone 



IN THE ANGLO-PARIS BASIN 



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40 



10- 



^30 



^20 



--10 



0-^0 

Fig. 




I (VI) 

l(v) 



16. Correlation of Lower Gault sections at Horton Hall and Folkestone. 



4 o MIDDLE ALBIAN STRATIGRAPHY 

By- Pass. Division 4 (iii) contains species of Hoplites (H.) that are found in the upper 
part of the spathi Subzone, and condensed in the ' upper dentatus-spathi nodule bed ' 
in the northern Weald. 

In the most northern cut of the old W. field, situated S. of Horton Wood, the top 
of the spathi Subzone was seen in 4 (iii). This consists of 1 foot 6 inches of shelly clay 
containing numerous crushed Hoplites (H.) some with well developed lautiform 
ribbing. The remainder of 4 (iii) in this cut contains numerous Inoceramus con- 
centricus but no ammonites were found by the author either in these clays or in 4 (iv) . 
Anahoplites intermedius appears in 5 (i) and this level is taken to mark the base of the 
intermedins Subzone. 

Before describing the remainder of the Lower Gault here, the correlation of the 
spathi Subzone sediments with the sequence at Selborne (Owen 1963a ; 43-4) will 
first be considered (text-fig. 14). Division 3 (i) at the Horton Clay pit contains the 
same fauna as Beds 1-3 at Selborne. On faunal and lithological grounds, 3 (ii) may 
be correlated with Bed 4, 3 (iii) with Bed 5, and 3 (iv) with Bed 6 at Selborne. 
Division 4 at the Horton Clay pit represents Beds 7-9 and the remainder of the 
sediments of the spathi Subzone not yet exposed at Selborne. The correlation of the 
Folkestone and Horton Clay pit sections is shown in text-fig. 16. 

intermedius Subzone 

The sediments from the base of 5 (i) to approximately 1 foot (0-305 m.) below the 
top of 5 (iii), a total thickness of 20 feet (6-096 m.), contain a typical intermedius Sub- 
zone fauna. The ammonites are quite often of good size (up to 4-5 inches (0-127 m -) 
in diameter) but crushed flat. Anahoplites intermedius, A. praecox, A. mantelli and 
A . planus are common to within 6 feet (1-829 m -) °f the top of 5 (iii) but then decline in 
numbers above, with Inoceramus concentricus becoming the dominant fossil. 

niobe Subzone 

At a level about 1 foot (0-305 m.) below the top of 5 (iii), Dimorphoplites niobe 
appears sparingly together with Anahoplites planus, Hamites tenuicostatus and 
numerous /. concentricus. In 5 (iv) partly crushed ammonites and bivalves occur in the 
cement-stone nodules, and crushed fossils occur in the interstitial clays ; the stony 
lenticles are original sedimentary features. The ammonites include Anahoplites 
planus, Dimorphoplites niobe, D. spp. The same fauna occurs in 6 (i) and (ii). The 
niobe Subzone is represented, therefore, by 9 feet (2-743 m.) of sediments. 

subdelaruei Subzone 

This subzone appears to be represented only within 6 (iii) and has yielded species 
of Mojsisovicsia including M. subdelaruei and M. remota. 

meandrinus Subzone 

Division 6 (iv) contains shell seams which, near the top, yield pyritised fossils. The 
fauna is typically that which occurs in Bed IV and the basal few inches of Bed V at 
Folkestone classified with the meandrinus Subzone. Three shell seams at depths of 
approximately 2 feet 4 inches (0-711 m.), 3 feet 4 inches (1-016 m.), and 4 feet 4 inches 



IN THE ANGLO-PARIS BASIN 



4i 



(1-321 m.), from the top of 6 (iv) have yielded ammonites suggesting a correlation 
with the basal 2 inches (0-051 m.) of Bed V at Folkestone. 

nitidus Subzone 

A typical nitidus Subzone fauna has been obtained from 6 (v) (Owen 1963a, 46) 
preserved in a manner identical to that of Bed V at Folkestone. No diagnostic 
ammonites were found by the author in 6 (vi) or (vii) and it is still uncertain whether 
these sediments are of nitidus or daviesi Subzone age. 

? daviesi Subzone 

In 1963, the author stated that the daviesi Subzone was absent. However, a few 
phosphatic nodules from the top of 6 (vii) have yielded ammonites including Ana- 
hoplites planus and Euhoplites truncatus together with /. concentricus. These occur 
immediately below the basal cristatum nodule bed at the base of Division 7. In the 
absence of Anahoplites daviesi it is not yet possible to determine whether these 
deposits represent this Subzone or not. 

(viii) HASSOCKS TO EASTBOURNE 

The only section in the Lower Gault now available east of Small Dole is to be seen 
above the Folkestone Beds in Messrs Hudsons Ltd's pit at Hassocks (text-fig. 17). 



Bed 



L 1 1 h o I o g y 



White to buff spherical septarlan phosphatic nodules in weathered 
gray clay. A scattered Una occurs at the base and a scattered 
line 9 Inches above It. 



Dank grey clay with patches of glauconltic sand which become less 
marked upwards. The clay Is well bedded and slightly shaly. 



Grey coarsely sandy highly argillaceous glauconltic loam. 



Loam streaked orange and greyish with grey clay content 
increasing upwards and passing down into brownish loam which tills 
hollows in the hgri helow. . 



1 Streaked ferruginous sand and iron pan guttered and contorted. 



Folkestone Beds 



3- 



1- 1 



7 
8 9 
5 9 
3 10 



Fig. 17. Basal Gault and Gault-Lower Greensand junction beds at Hudsons Ltd's Hudsons 
Red Sand pit, 1400 yds W. of Hassocks railway station and 350 yds S. of the B 21 16 road, 
Hurstpierpoint, Sussex (TQ 29121552). 



42 MIDDLE ALBIAN STRATIGRAPHY 

This section has been discussed by Osborne White (1924 ; 29) Kirkaldy (1935 ; 526) 
and Casey (1961a ; 559-560). The eodentatus Subzone is present within Bed 4, and 
the lyelli Subzone within beds 4 and ?5. 

Further east in Sussex there is very little information about the Lower Gault other 
than that recorded by Clement Reid (1898), Jukes-Browne (1900) and Osborne 
White (1924 & 1926). Spath demonstrated that at Ringmer the daviesi Subzone is 
represented (1926a ; 154) and it seems from the well records (Edmunds 1928) that the 
Middle Albian sediments probably maintain the thickness seen at Small Dole and may 
well thicken a little. The major increase in thickness of the Gault eastward is mainly 
explained by the change in facies from Upper Greensand to Gault. This is certainty 
the case in the Lewes area where the proven Upper Gault is very thick. 

The discovery of a nodule bed of spathi Subzone age in the sea-bed ESE. of Beachy 
Head was used by the writer as evidence of an attenuation of deposits of this age in 
that area (Owen 1963a ; 46, 48, text-fig. 2). However, phosphatised Hoplites (H.) 
occur in Division 4 at the Horton Clay Pit where the sequence is very thick, and the 
record of the Eastbourne Waterworks well given by Jukes-Browne (1900, 118) is 
probably misleading. 

B. Isle of Wight, and Dorset Coast 

This section deals with the outcrops in the Isle of Wight, from Punfield to Osming- 
ton, and from near Seatown to the Devon border (text-fig. 18). Of necessity the 
account is very incomplete for the exposures are seldom good and the facies is such 
that ammonites are uncommon except at a few horizons in the various localities. 
For this reason no correlation diagram is given on this occasion. Despite the 
difficulties, useful results have been obtained. 

(i) ISLE OF WIGHT 

The Carstone, and the overlying Gault (aptly named the ' Blue Slipper ') describe, 
except in the centre of the Island, narrow outcrops from Redcliff near Culver in the 
east to Compton Bay in the west. This is in response to the high dip on the northern 
limb of the Sandown and Brighstone anticlines respectively. Where the two axes 
meet in the centre of the Island there occurs a structural ' no-man's land ' with com- 
paratively gentle northerly dips and thus a broader outcrop. An outlier of Chalk 
and Upper Greensand in the southern part of the island is fringed by outcrops of 
Carstone, and Gault dipping gently south. The Carstone and Gault have been 
described in stratigraphical detail notably by Bristow et al. (1889), Jukes-Browne 
(1900 ; 126-130), Osborne- White (1921), Kitchin & Pringle (1922a ; 160-161), Spath 
(1943 ; 741-743), and Casey (1961a ; 512-515), but there are many other references to 
them in the literature. The Gault is responsible for the major landslips on the 
southern coastline, and much of the outcrop is obscured by slipping, sludging, and 
deep weathering. The sections that are available are not always easy to work and 
fossils are far from plentiful. 



Fig. 18. Sketch map showing positions of sections in South West England discussed in the text. 



IN THE ANGLO-PARIS BASIN 43 

Bristow et al. (1889), Jukes-Browne (1900), and Osborne-White (1921) all give a 
roughly uniform thickness of 100 feet (30-48 m.) for the Gault throughout the Island. 
However, this is certainly not correct for although the thickness is about 100 feet 
(30-48 m.) at Redcliff, it is reduced to about 65 feet (19-81 m.) at Compton Bay, and 
may be over 100 feet (30-48 m.) in the southern part of the Island. Kitchin & 
Pringle (1922 ; 160-161) recognised that Middle Albian sediments of the ' interruptus 
Zone ' were present at Culver and in the south of the Island, but they considered that 
the Gault in Compton Bay was wholly Upper Gault. They based their conclusion 
on the old record of Inoceramus sulcatus (Norman 1887 ; 70), but it will be shown 
below that this argument together with their view that the ' — so-called " Carstone " 
of this locality — ' did not represent the true top of the Lower Greensand, is com- 
pletely fallacious. Spath (1926b ; 422, and in Jackson 1939 ; 74) considered that the 
Gault represented only the dentatus Zone and that the ' lower benettianus (=inaequin- 
odum) zone ' passed into the Carstone beneath. This latter conclusion was confirmed 
by Casey (1961a ; 515) based on material collected by C. W. Wright and the author. 



(a) Redcliff 

The Gault in the hollow between Redcliff and the Upper Greensand face at the W. 
end of Culver Down (SZ 62758550) is badly slumped and overgrown. However, 
from time to time exposures of a few feet of clay dipping steeply NE. have been seen 
near the top and the base of the Formation. The Gault is here about 100 feet 
(30-48 m.) thick but it is impossible at this time to obtain an accurate measurement. 
From sections exposed near the base it can be seen that there is a fawn band within 
six feet (1-828 m.) of the junction with the underlying pebbly Carstone. This fawn 
band contains crushed Hopiites (H.) spp. with pyritic films replacing the shells, 
together with a few part-phosphatised specimens. On the basis of the ammonites 
so far seen, a basal spathi Subzone age is indicated. However, a similar unit at Bon- 
church has yielded rare but definite lyelli Subzone fossils. 

Mr. J. McA. Hart collected a pyritised Euhoplites of Upper Gault aspect from a 
small exposure near the top of the Gault and below Jukes-Browne's Division A. This 
indicates that at Redcliff the lower part of the Upper Albian is within the clay facies. 



(b) Rookley 

Perhaps the most important section available in the Isle of Wight at this time is 
exposed in the extensive workings of Island Bricks Ltd., at Rookley. The sequence 
extends from well down in the Carstone up into the Gault and is shown graphically 
in text-fig. 19. It has never been described in detail but has been mentioned by 
Pritchett & Jackson (1941). The pit is cut by an E.-W. fault down-throwing to the 
south, and the southern part of the section is tectonically disturbed. The sequence 
north of the fault dips NW. at 6° and shows variations in the thickness of certain 
beds which cannot be ascribed to a later tectonic cause. These are here considered 
to be due to slumping before consolidation of the sediment. 



44 



MIDDLE ALBIAN STRATIGRAPHY 

LI t h o log y 



Weathered mottled grey clay. 



Ferruginous marl band with phosphatic nodules. 



Dark grey clay streaked with ochreous seams. 



Ochreous clay with occasional lenticles of ferruginous 
marl & large spherical or elongated septarian phosphatic nodules. 



Ochreous mottled clay passing down into Bed 9 below. 



Highly ferruginous marl. 



Dark grey clay with partly phosphatised fossils the shells 
being replaced by films of pyrlte. 



Fawn— grey clay with occasional scattered phosphatic 
nodules. At base part-phosphotlsed fossils occur with pyrltic shells^ 



Dark grey clay. 



Fawn grey clay. 



Dark gritty glauconitic clay. 



Fawn grey sllty clay with burrows of dark grey clay and 
crushed pyrite replaced shells of Inoceramus concenfricus. 



Glauconitic dark grey micaceous clay with streaks of 
glauconite sand. 



(ll)Streaked grey gritty clay with pockets of sand & glauconlte. y/ 



(i) Lenticles of false-bedded glauconitic pebbly loam. 



7 



TOP OF CARSTONE 
Variegated dark and light brown ferruginous grit separated 
from Bed 1 by a thin seam of iron pan. Top few Inches with 
many small pebbles and thin seams of pan. Gritty pale 
phosphatic nodules occur scattered at about middle. Nine 
inches from base there occur crushed ammonites, rarely 
part-phosphatlsed, with the shell. 




Ins M 




1-2 9- 



3-4 



8- 



9-10 



— 1CM2 

— 9 5 

— 10-19 



3- 



2- 



— 


5 




0-6 


3 


8 




to 


4 


6 



oJ 



Fig. 19. Middle Albian sediments at Island Bricks Ltd's Rookley Brickworks, situated 
600 yds ESE. of the school, Rookley, and 150 yds NW. of the A 3020 road, South Arreton, 
Isle of Wight (SZ 5I338395)- 



IN THE ANGLO-PARIS BASIN 45 

Bed 5 of the Carstone contains crushed filmy shells of ribbed ammonites. Very 
rarely these are partly phosphatised and can be identified as Hopiites (Isohoplites) 
spp. including H. (I.) eodentatus (e.g. BMNH., C 73358 author's colln., figured Casey 
1965 ; 538, text-fig. 202 g.h.) indicating an eodentatus Subzone age. Beds 1-6 of the 
Gault have not yielded fossils and may represent the lyelli Subzone known to be 
present in the Ventnor area to the south. Beds 7-1 1 can definitely be classified with 
the spathi Subzone. Bed 7 contains crushed pyritic ammonites, some partly phos- 
phatised, including the typical H. (H.) spathi and H. (H.) dentatus marking the base 
of the spathi Subzone. Bed 8 also contains crushed Hopiites (H.) spp. with pyritic 
tests which decompose very rapidly on exposure. Beds 9-10 have not yielded fossils, 
but Bed 11 has yielded a few fragments of large Hopiites (H.) which still suggest the 
lower part of the spathi Subzone. No fossils were found in Beds 12-14. 



(c) Compton Bay 

In view of Kitchen & Pringle's statement that no Lower Gault is present in Comp- 
ton Bay (1922 ; 161) it was particularly fortunate that a good section has been ex- 
posed during recent years. The true Gault here was stated by Strahan (in Bristow 
et at. 1889 ; 63) to be 95 feet (28-956 m.) thick excluding the passage beds to the 
Upper Greensand but this is far in excess of the true figure. The very high angle of 
true dip seen in the cliff, levels off sharply at no great depth below beach level due to 
a slight flexure and change in direction of apparent dip. On a very accurate 
measurement based on the detailed sequence given in text-fig. 20, the thickness 
is little more than 65 feet (19-812 m.). 

The phosphatic nodules at the top of Bed 8 of the Carstone have yielded Hopiites 
(Isohoplites) eodentatus indicating that Subzone. No ammonites have been found in 
either Beds 1 or 2 of the Gault and their exact Subzonal age is unknown. However, 
the species of Hopiites (H.) in Bed 3 indicate the basal part of the spathi Subzone and 
it is possible that both Beds 1 and 2 are of lyelli Subzone age. Apart from Bed 3, the 
only other ammonites found were crushed Hopiites (H.) sp. at the base of Bed 10, at 
which point a shelly facies appears. One is tempted to compare this junction be- 
tween the pyritic facies below and the shelly facies above, with a similar junction in 
the spathi Subzone sequence in the Nyewood-Wrecclesham area of the outcrop in the 
Weald. However, such a correlation may well be more apparent than real. Beds 3 
to the base of Bed 10 can, therefore, be classified with the spathi Subzone. How much 
of the overlying sediments belong to the spathi Subzone is not yet known, as also 
whether any other Middle Albian Subzones are represented. However, there is no 
doubt that there is a substantial thickness of ' Lower ' Gault present at Compton 
Bay. 



(d) Ventnor to Niton 

A complete section of the Carstone is exposed in the sea-cliff extending from 
Dunnose south-westwards to the esplanade at Bonchurch ; the stretch of coast named 



4 6 



MIDDLE ALBIAN STRATIGRAPHY 



LI t h o I ogy 



Ft Ins M 



Deeply weathered gr«y clay the detailed lithology of which is 
obscure. In the upper 1 foot the sediment consists of dark grey 
clay This is followed by Division A of the Upper Greensand. 



Very glauconitic sllty weathered clay. 



Dark silty, micaceous, glauconitic, sparsely shelly clay becoming 
more glauconltic in the upper 3 feet. 



Darkish fine-grained micaceous clay becoming darker upwards 
with increase of the silt and very f i ne-grained glauconitc fraction, 
No fossils seen. 



Fawnish silty clay containing plant remains at top. 



Bed 6 becomes tougher and more silty with scattered pockets 
of glauconitic silt. Bed 7 in turn passes by wisps into Bed 8. 



Darkish grey micaceous silty clay with obscure pyritic shell 
f ragments. 



Fawn gritty clay. 



Dark grey micaceous gritty clay. 



Fawn gritty clay band with black septarlan phosphatlc nodules. 



Hard blocky silty dark grey clay micaceous and weathering 
battleship grey. 



Dark gray slightly mottled clayey fine grained micaceous loam, 
weathering light grey. 

BASE OF THE GAULT 



Glauconitic micaceous fine soft silty sandstone with pip«s of dark gr«y clay; 
b J?S«WA th *r?. f « rr| Jginous. Small pebblc-s in clay e y bottom 6-8 incnes. Sandy 
nnosphol cs of top. _ 1__ 





20- 


10 


6 


2 





9 


°15- 


6 







- 


A 


6 - 




10- 


A 


6 


6 


- 


8 







5- 


4 


o - 


1 


6 . 


3 


2 


A 


4 


1 


9 




J 



Fig. 20. Section of the Gault exposed in the sea-cliff about 200 yds NW. of Compton Chine, 
Compton Bay, Freshwater, Isle of Wight (SZ 36708524) . 



IN THE ANGLO-PARIS BASIN 47 

Monks Bay. Above this, the basal beds of the Gault are occasionally well exposed 
at the top of the cliff, but the remainder of the Gault is badly slumped in the Under- 
cliff itself. Other sections are known from Ventnor, Steephill, and from Reeth Bay, 
Niton and round St. Catherine's Point and are mentioned below. An ammonite 
described by Spath as Anahoplites mimeticus (1925 ; 131, pi. X, fig. 7a, b) was alleged 
to have come from the ' Carstone ' of Niton, Isle of Wight. However, the preserva- 
tion of the holotype BMNH., C 30535 indicates that it is definitely not from the 
Carstone but from an horizon in the Gault possibly above the spathi Subzone sedi- 
ments ; it is possibly a species of Hoplites (H.) with a smooth outer whorl. The 
specimen figured by Casey (1966 ; 547, text -fig. 207a, b, C. W. Wright Colin., 9983) 
as Anahoplitoides mimeticus Spath which he states came from the top of the Carstone 
(eodentatus Subzone), of Bonchurch, is preserved in a manner quite unlike any of the 
material from the top of the Carstone and C. W. Wright has informed me that it was 
picked up loose. It must come from a higher horizon in the Gault than the proved 
spathi Subzone sediments. However, Hoplites (Isohoplites) eodentatus does occur in 
the top part of the Carstone at Bonchurch but the preservation is the typical sandy 
phosphate. It might be mentioned here that the specimen of Hoplites vectensis from 
the Carstone near Niton mentioned by Spath (1925a ; 128 L.F. Spath Colin. No. 238 
= BMNH., C 30555) is indeed from the Carstone and is an external mould without 
the peripheral area. Nonetheless, it is almost without doubt a specimen of H. 
(Isohoplites) . 

The few feet of Gault immediately overlying the Carstone at Monks Bay has 
yielded, from a fawn band, crushed and partly phosphatised Hoplites (H.) spp., 
specimens of which are in the British Museum (Nat. Hist.) L. F. Spath Colin. An 
external mould of a Beudanticeras sp. in an identical matrix is preserved in the 
Institute of Geological Sciences (GSM., Zn 1483 also L. F. Spath Colin.) and indicates 
the presence of the lyelli Subzone. A pyritic specimen of Lyelliceras is in fact known 
from this locality and was figured by Spath (1931 ; 320 pi. XXXIII, fig. i5a-c, 
BMNH., C 32845). Further evidence of the presence of sediments of lyelli Subzone 
age is provided by ammonites from the basal Gault near the Gas House, Gas House 
Hill, Ventnor (SZ 56857747) preserved in the Sedwick Museum. These consist of 
black brittle phosphate steinkerns without the shell, typical of the lower fawn band, 
and include Beudanticeras sanctaecrucis and Hoplites (H.) spp., one of them (B 42586) 
with pyritic inner whorls like that of the Lyelliceras mentioned above. C. W., & 
E. V. Wright have recorded Protanisoceras moreanum from west of Luccomb Chine 
(1942 ; 286). 

More definite information about the higher part of the Gault is provided by the 
section in the cliff SW. of Steephill Cascade, Ventnor (SZ 55467707). Here the 
Gault dips seaward becoming much steeper in the foreshore landward of an old 
slipped mass. Dark grey gritty pyritic clay with rolled pieces of phosphatised 
Hoplites (H.) spp. occurs along the axis of the ' fold ' and is overlain by sparsely shelly 
clay in which ammonites have yet to be found. The cliff behind these foreshore 
exposures is deeply weathered at this time. 



4« 
Bed 



12 



11 
10 



MIDDLE ALBIAN STRATIGRAPHY 

Llthology 



Weathered blocky marly clay with ferruginous streaks. 



Homogeneous light grey clay tending to be hard and blocky 
with occasional streaks of silt. Pyritic shell seams occur 
at 4 and 11 feet above the base and contain Inoceramus 
concenlricus 



Y 

A 



Grey blocky micaceous silty clay with streaks of white silt at 
base. A pyritic shell seam occurs 2 inches from base. 



Homogeneous grey silty clay. 



Tough grey silt 



Light fawny grey silty clay with pyritic fossils. 



Grey silt. 



Fawn clay with dark burrows. 



Soft dark grey silty micaceous clay with some fine 
glauconi t e 



Tough silty homogeneous fawnish clay. 



Badded pyritic silty clay; the top 4 inches being more silty 
and g lauco n i t ic. 



Blocky grey silty micaceous clay. ,i. 



Obscured interval 



Mottled pyritic clay, 



Obscured interval 
with 

mottled weathered greyclay at the base 



Dark grey-brown blocky loam with grey clay streaks. 



Remainder of CARSTONE 



Ft Ins M. 



16 6 




Fig. 2i. Gault section in cliff below old coast road 50 yds NW. of Cliff Cottage and 
360 yds SSE. of Blackgang Hotel, Blackgang, Chale, Isle-of- Wight (SZ 48877644). 



IN THE ANGLO-PARIS BASIN 49 

(e) Blackgang 

The section in the Carstone and Gault at Blackgang shows that the sequence has 
changed fairly considerably in the mere 4! miles from Ventnor. The section given 
in text-fig. 21 exposed below Cliff Cottage, Blackgang, shows that the sediments are 
generally coarser in grade. It is exposed at the summit of a cliff of Sandrock Series 
and in wet weather is dangerous. 

Bed 8 of the Carstone is probably of eodentatus Subzone age, but Hoplites (Iso- 
hoplites) has not yet been found here. Unfortunately, the lower 8 feet (2-438 m.) of 
the Gault is not clearly exposed but it certainly contains at least one fawn pyritic clay 
band which has not yet yielded fossils. The only ammonite seen in Bed 3 was a 
crushed Hamites (H.) sp. 4 inches (o-ioi m.) below the top which indicates the spathi 
rather than the lyelli Subzone. Bed 12 has also yielded crushed Hoplites (H.) spp. 
which indicate the spathi Subzone. No other ammonites have been found higher in 
the section but /. concentricus still occurs 11 feet (3-352 m.) up in Bed 13. 

A section below Gore Cliff about 825 yards SE. of Cliff Cottage shows higher Gault 
(text-fig. 22). Unfortunately the two sections probably do not overlap although 
there is an obscured interval of 12 feet (3-657 m.) at the base of the Gore Cliff sequence. 
/. concentricus is present in the top 1 foot 6 inches (0-457 m.) of ' Bed 1 ' showing it to 
be still of Middle Albian age, but no other age indicative fossils are yet known from 
this section. 

Certainly some of the lower part of the Gault here is of spathi Subzone age. How- 
ever, the specimen of Hoplites aff. vectensis recorded by Spath (1925 ; 128, BMNH., 
C 890) and said to be from Blackgang is in fact identical in preservation to specimens 
from the top of the spathi Subzone at Osmington, Dorset, from whence it undoubtedly 
came. 

(ii) BALLARD CLIFF TO OSMINGTON 

The early accounts of the Gault in this coastal area of Dorset were given by Strahan 
(1898) and Jukes-Browne (1900). This work was revised by Wright {in Arkell 
1947b ; 178-194), and there is no new information to add to his lithological account 
for the sections have deteriorated considerably. However, his Subzonal classifica- 
tion of the basal beds requires revision. Wright redescribes, as far as it is possible, 
the sections at Punfield Cove, Swanage (SZ 03878110), Flower's Barrow, Worbarrow 
Bay (SY 86388045), Lulworth Cove (East SY 82867988, West SY 82427988), 
Durdle Cove (SY 80578028), White Nothe, and Black Head, Osmington, covering in 
all a distance of 35 miles (text-fig. 18). 

Beds 1 and 2 at Flower's Barrow, Worbarrow Bay, are apparently of the same age 
as the ferruginous clay with concretions at Black Head, Osmington, as Wright stated. 
However, the fauna from these sediments at Black Head, first recorded by Cunning- 
ton (1929) is not of ' benettianus ' Subzone age as Spath originally thought (Wright 
in Arkell 1947b ; 181) for all the species of Hoplites (H.) which occur, such as H. (H.) 
dorsetensis and H. (H.) vectensis, can be matched in the highest part of the spathi 
Subzone in the Weald and elsewhere. Even Spath was to change his mind about the 
Subzonal age of these two species, placing them in the intermedins Subzone (1942 ; 

D 



50 



MIDDLE ALBIAN STRATIGRAPHY 



Bed 



LI thology 



Dark grey sllty clay with wisps of glauconlte and sand, shelly 
with scattered pyrite nodules. 



Homogeneous dark grey clay with pyrite nodules and crushed 
fossils with the shell preserved. 



Blocky homogeneous dark grey clay with pyrite nodules and 
occasional bivalves with the shell preserved. 



Passing down at the base into; 



Glauconitic silty clay with rafts of glauconlte sand. 



Fawn clay with pyritic nodules, and phosphatic nodules at the top. 



Dark grey glauconitic silty clay with Inoctramus conctnlricus 
preserved with the shell. 



Sequence obscured by scree. 



Ft Ins M 



o o 



9- 



9 



1 6 



3 4 



2 5 5- 



1 5 



3- 



12 O 2 - 



1- 



0-> 



Fig. 22. Cliff section of Gault at top of undercliff below Gore Cliff, 480 yds ESE. of South 
View House, Blackgang, Chale, Isle of Wight (SZ 49437590). 



IN THE ANGLO-PARIS BASIN 51 

675). In this, he was very nearly right, for the concretions at Black Head yield, 
albeit very rarely, early forms of Anahoplites of the intermedins group. These 
include the specimen figured by Spath as A. mimeticus (1927 ; 188, pi. XVII, fig. 8a, b) 
which belongs to A. osmingtonensis sp. nov., and A. grimsdalei sp. nov. which is the 
direct forerunner of A . evolutus a form found at the base of the intermedins Subzone. 
These early Anahoplites are associated with the usual species of Hoplites (H.) of this 
bed, however, it is important to note Cunnington's remark (1929 ; 126) : 'Ana- 
hoplites — are scarcer, but wherever one is found there are almost always others or 
fragments of others in the same block '. I have not yet found Anahoplites in this line 
of concretions containing an upper spathi Subzone fauna. This might be purely a 
collecting error, for the matrix and mode of preservation of the specimens of Ana- 
hoplites is identical to that of the other fossils of this bed and this is very distinctive. 
From a morphological point of view these are unquestionably earlier than the basal 
intermedins Subzone species of this genus, e.g. A. evolutus (p. 151). Equally certain, 
they are not earlier than the high spathi Subzone concretions ; that is, they are not of 
lyelli Subzone age. The sections in this area are shown in Arkell (195 1 ; Fig. 4). 

Deposits of lautus Zone age are also present in this area (Cunnington 1929 ; 129 : 
Spath 1943 ; 743 : Wright in Arkell 1947 ; 193) but the position in the section of the 
material picked up loose has yet to be determined. 

(iii) THORNCOMBE BEACON TO BLACK VEN 

The account of the sections on Golden Cap, and Black Ven, given by Jukes-Browne 
(1900 ; 182-189) was followed fourteen years later by the very important detailed 
account by Lang (1914) who also discovered the formation on Stonebarrow. To this, 
additional information was added in Lang & Thomas (1936), and these sections to- 
gether with that on Thorncombe Beacon east of Seatown have more recently been 
described by Welch (in Wilson, Welch, Robbie & Green 1958 ; 139-150). Here 
again, there is nothing to add to the lithological account but a re-examination of the 
ammonites has provided a little, but important, additional information. The 
sediments classified with the Gault are much thinner in this area of the coast. 

Bed 1 of Lang (1914) yielded Anahoplites praecox both at Black Ven and Stone- 
barrow (1936 ; 310). Bed 2 on Stonebarrow has also yielded A. praecox including 
one specimen BMNH., C 15661 which is very close indeed to the neotype of ' Dimor- 
phoplites ' alternatus, which is in reality a very coarse development of A . praecox 
(p. 153). A. praecox also occurs at Chart on Goyle in a matrix which is almost cer- 
tainly the unweathered representative of Bed 2 (BMNH., C 68394-6). Beds 1 and 2 
definitely belong to the intermedins Subzone. According to Spath (e.g. 1943 ; 744), 
Bed 3 contains both intermedins Subzone and varicosum Subzone ammonites. This 
is untrue. BMNH., C 41035 from Bed 3, recorded by Spath as Epihoplites aff. 
trifidus, is in reality an early transition between Hoplites (H.) and Dimorphopiites 
consistent with an intermedins Subzone age. The ' Idiohamites of the turgidus 
group ' (BMNH., C 41038) is a Protanisoceras (H.) cf. nodosum, also indicating an 
intermedins Subzone age. Another specimen BMNH., C 41035 from Bed 3 is here 
identified as Anahoplites cf. intermedins. 



52 MIDDLE ALBIAN STRATIGRAPHY 

There is, therefore, no evidence of the presence of Upper Albian sediments in 
Lang's Bed 3 and this is consistent with the distribution of Inoceramus concentricus 
and i". sulcatus. I. concentricus is known from Beds 1, 2, and 3 (e.g. Lang Colin., 
BMNH., L 55076 from Black Ven) both on Black Ven and Stonebarrow. Specimens 
of I. sulcatus are known from Black Ven (e.g. BMNH., L 55368-71 Grimsdale Colin.) 
preserved without the shell in glauconitic sandstone which suggests Lang's Bed 10, 
certainly no lower horizon. The record of Anahoplites planus from Lang's Bed 10 by 
Spath (1943 ; 744) is an error. The Middle-Upper Albian boundary falls somewhere 
between the top of Bed 3 and ?the base of Bed 10. 

The above indicates that Kitchin & Pringle's statement that no Lower Gault 
exists at Black Ven is quite fallacious (1922 ; 163). This statement is the more 
incredible when one realises that they had never examined the section and apparently 
had overlooked Lang's paper of 1914. There may well be a non-sequence in these 
sections but at this time there is no evidence to indicate its extent. 

No sections further west on the Devon Coast have been examined by the writer. 

(iv) CONCLUSION 

The poor state of the sections in the Isle of Wight and on the Dorset Coast are 
particularly tantalising, nonetheless, some results can be drawn from this incomplete 
information. It is apparent that in the Isle of Wight the eodentatus Subzone is 
represented at the summit of the Carstone ; the lyelli Subzone is represented in the 
lower part of the Gault at least in the southern part of the island ; and the spathi 
Subzone sediments are well developed. The intermedins Subzone is probably repre- 
sented but the conclusive proof is not yet to hand. 

By Worbarrow Bay and Osmington the fossiliferous concretions very near the 
base of the Formation are of uppermost spathi Subzone age, and there is evidence of 
lautus Zone sediments near the top of the Gault in the Osmington- White Nothe area. 
In the sea-truncated outliers between Seatown and Lyme Regis the lowest fossilifer- 
ous sediments are of intermedins Subzone age. As one proceeds westwards from the 
Isle of Wight, therefore, the lowest fossiliferous sediments become later in age (text- 
fig. 23). The intermedins Subzone is widely represented by sediments in the deeper 
parts of the Wessex Basin ; for example in the Petersfield and Winchester districts, 
Hampshire (p. 69), at Didcot, Berkshire (p. 63), Devizes, Wiltshire (p. 60), and 
possibly at Okeford Fitzpaine, Dorset (p. 56). Its presence in the Isle of Wight, and 
in the Dorset coast sections as far west as Osmington should not be discounted. 
Across the Channel at Cauville on the French coast NE. of Le Havre, there occurs, 
above a remanie bed of basal dentatus Zone age, even later sediments of niobe Subzone 
age (p. 107). 

C. The outcrop from Devon to Bedfordshire 

There is no information available about Middle Albian sediments inland in the 
area W. of the River Axe. Neither is there any further stratigraphical information 
available at the outcrop from the valley of the Axe to Okeford Fitzpaine, N. Dorset, 



IN THE ANGLO-PARIS BASIN 



53 



other than that recorded by Jukes-Browne (1900 ; 163-4), Welch and Robbie (in 
Wilson, Welch, Robbie & Green 1958 ; 148-152) 1 , Reid (1903 ; 34-35), Osborne- 
White (1923 ; 49-50) and Smart (1955 ; 43-4)- It is apparent that Middle Albian 
sediments occur north-eastwards from the area of Beaminster for although am- 
monites have not been found, Inoceramus concentricus has been recorded from a 
number of sections and in this context definitely indicate a Middle Albian age. From 
the coast between Thorncombe Beacon and Black Ven (p. 51), Middle Albian 
sediments thin markedly inland in places to less than 10 feet (3-04 m.) to thicken 
again in the area of Toller Porcorum (SY 562974) S. of Evershot, and also in the out- 
crop N. of Evershot eastwards from West Chelborough (Welch and Robbie in Wilson 
et al., 1958). The Gault continues to thicken eastwards and in the region between 
Alton Pancras and Ansty, Smart records a thickness ranging from 25-35 feet (1955 ; 
42-4). The increasing thickness is maintained up to Okeford Fitzpaine. 



w 

Black Van 




Osmington 


Islaof Wight 


E 

Sussex 




"\ 


-— iiate) 


ml ermediu s 




^^--^^ spa th 1 

^^-vT~-^_ (early) 

\ \ 





Fig. 23. Sketch section, from W. to E. across the Late Jurassic-early Cretaceous modified 
Wessex basin in the area of the south coast, demonstrating the transgressive nature of the 
Middle Albian sediments and the diachronous nature of the base. 

It is very regrettable that no good sections are now available throughout this long 
strip of outcrop (text-fig. 18). The sequence seen on the coast between Thorncombe 
Beacon and Black Ven, with its development of the intermedins Subzone of the 
loricatus Zone has passed in the area of Okeford Fitzpaine to a sequence showing the 
development of the eodentatus, lyelli & spathi Subzones of the dentatus Zone. In this 
latter area it is underlain by deposits of mammillatum Zone age absent at the coastal 
section to the SW. This difference in sequence is made somewhat significant by a 
comparison with the sections in the Pays de Caux in northern France (p. 101), and is 
discussed later in the section dealing with the conditions of deposition (p. 142). 



1 It is worth stating here that the stream and river sections described by the Survey officers are only 
well visible in periods of drought (cf. Dewey 1934 ; 42). 



54 MIDDLE ALBIAN STRATIGRAPHY 

(i) OKEFORD FITZPAINE (DORSET) 

The section at the Okeford Brick & Tile Works situated about | mile E. of the 
village of Okeford Fitzpaine on the road to Shillingstone is no longer visible. It was 
first described by Newton (1896 ; 198 : 1897 ; 66-68) from notes and material provided 
by the Misses Forbes and Lowndes, then by Jukes-Browne (1900 ; 162), Reid 1903 ; 
34-35), and Osborne White (1923 ; 48). Text-fig. 24 is taken from the account given 
by Newton (1897, 67-8) with additions from Jukes-Browne. Spath (1925 ; 73 
pi. V, fig. 6) figured one of Newton's specimens of 'Acanthoceras mammillatum ' as 
Douvilleiceras inaequinodum (Quenstedt) so demonstrating the presence of the 
inaequinodum Subzone to which Casey assigns the base of the Gault here (1961a ; 
565) ; now included in the eodentatus Subzone. Spath also demonstrated the 
presence of the benettianus Subzone (i.e. lyelli Subzone) by the occurrence of Hopiites 
(H.) ' pseudodeluci ' Spath (type locality, 1925a ; 120) and forms close to H. (H.) 
benettianus (J. de C. Sowerby) (1925a ; 117-8), together with Beudanticeras probably 
laevigatum and 'Anahoplites of mimeticus type ' (1926a ; 147). 

The material described by Newton is in the British Museum (Nat. Hist.). A re- 
examination of the fossils and a careful reading of Newton's account (1897) has 
provided the following important stratigraphical information. All the specimens 
were undoubtedly indigenous and not semi-derived. The three fragments (BMNH., 
C 6856-8) recorded by Newton as Acanthoceras mammillatum described by Spath as 
Douvilleiceras inaequinodum could well belong to one partly phosphatised individual. 
The nacreous shell was clearly preserved and the matrix adhering to it consists of the 
bluish grey micaceous clayey sand with glauconite of Bed 3. The specimen could not, 
therefore, have come from Bed 2. The specimens of Ostrea leymeriei (BMNH., 
L 11579 figured specimen, L 11591) have traces of the same sediment adhering to 
them as that of the specimen of D. inaequinodum. Moreover, internally there is the 
same blackish phosphate. It would seem also that these come from Bed 3 and not 
Bed 2 (cf. Newton 1897 ; 68). 

If this is the case then Bed 2, which Jukes-Browne (1900 ; 163) considered to be a 
separate lithological unit and from which he records no fossils, together with Bed 1 
may correspond to sediments at Dinton in the Vale of Wardour which have yielded a 
kitchini Subzone fauna (Casey 1956 ; 231, 1961a ; 564). Jukes-Browne considered 
that these two beds should possibly be grouped with the Lower Greensand. My 
reading differs from that of Casey (1961a ; 565) who states that the Gault here rests 
directly upon the Kimmeridge Clay. 

Two fragments of large specimens of Hopiites (H.) spp. (BMNH., C 6859-60) 
identified by Newton as Hopiites benettianus (1897 ; 70), one of which he figured, are 
preserved one with and the other without the nacreous shell in a ferruginous brown 
(weathered) and grey micaceous clayey sandstone. Bearing in mind Newton's 
remarks (1897 ; 67-8) this lithology indicates the upper part of Bed 4. The specimen 
figured by Newton (1897 ; 70, pi. 2, fig. 1, BMNH., C 6860) was subsequently made 
the holotype of Hopiites pseudodeluci by Spath (1925a ; 120-123) but due to its 
crushed state and lack of inner whorls the true nature of it is impossible to determine. 
Moreover, a specimen from Bed 5 at Badbury Wick shows a closely comparable outer 



IN THE ANGLO-PARIS BASIN 



55 



Bed 



Llthology 



Ft ins M 



(II) Dark-grey micaceous si I ty clay with phosphatlc nodules. 



V 
A 



(I) Shelly dark-grey sllty clay with glauconlta. 



Brown sandy rock with fossils In the upper part. 



Y 
"a 



Brown, green grey, and ye I lowlsh clayey micaceous loam, with 
part phosphatlsed fossils with the shell preserved, and small 
pebbles particularly In the lower part. 



Brown sandy Ironstone breaking Into small lumps. ' .J 
It 

Is 

Clean green sand. | o. 

4r 



d d ,0 



KIMMERIDGE CLAY 



8- 



11 



6- 



5- 



4- 



4 



2- 



5 



1- 



0-J 



Fig. 24. Section in Albian sediments (after Newton 1897, Jukes Browne 1900, & Osborne 
White 1923) formerly exposed at the old Okeford Brick & Tile Works, immediately S. of 
the Okeford Fitzpaine to Shillingstone road, 800 yds E. of St. Andrew's Church, Okeford 
Fitzpaine, Dorset (ST 81501080). 



56 MIDDLE ALBIAN STRATIGRAPHY 

whorl but the inner whorls are those of H. (H.) bullatus Spath. Bed 4 can definitely 
be classified with the lyelli Subzone even if no specimens of Lyelliceras, Beudanticeras 
or Protanisoceras have been preserved. A more typical lyelli Subzone fauna was 
recovered from the lower part of Bed 5. The ammonites described by Newton are 
preserved in two distinct lithologies, although they all possess remains of the nacreous 
shell and, except for one, are preserved as partly crushed clay steinkerns. They were 
re-identified by Spath as follows, to which my own comments are added. 

Hopiites interruptus Bruguiere 

(1) Hopiites pseudodeluci Spath (BMNH., C 6864) figured by Spath (1925a ; 121, 
pi. X, fig. 6) which is preserved in an identical manner to those of Bed 4 from which it 
probably came. 

(2) Hopiites sp. transitional between benettianus & paronai (BMNH., C 6863) 
according to Spath (1925a ; 115, 118). This specimen which has pyritic inner whorls 
is crushed ventrally, having come to rest on the sea floor on its venter. It is pre- 
served in fawn clay with glauconitic loam filled burrows. It is specifically indeter- 
minate. 

(3) Hopiites sp. benettianus, baylei group (BMNH., C 6862) (1925a ; 118) probably 
does not belong to either of these two species. 

(4) Newton's figured specimen (BMNH., C 6861), identified by Spath as Hopiites 
dentatus (J. Sowerby) (1925a ; 118), is preserved crushed in glauconitic sandy dark 
grey clay. 

Hopiites splendens J. Sowerby 

(5) The two small specimens (BMNH., C 6866-7) were identified by Spath as 
Beudanticeras probably laevigatum. They are preserved in exactly the same type of 
matrix as (2) above. 

(6) The larger specimen (BMNH., C 6865) was identified by Spath (1926a ; 147) 
as Anahoplites resembling A . mimeticus. It certainly is an Anahoplites, preserved in 
the same type of matrix as (4) above, and its occurrence is discussed below. 

Hamites sp. 

(7) In his description of Hamites attenuatus Spath (1941 ; 611 footnote) referred to 
the two specimens indicating that they might have been tuberculate and, therefore, 
generically distinct. A close examination shows that they are both Protanisoceras 
sensu-stricto, one of them (BMNH., C 6868) being P. (P.) barrense, the other (BMNH., 
C 6869) closely comparable to that species. They are both preserved in the same 
lithology as (2). 

The specimens (Nos. 2, 5, & 7 above) preserved in fawn clay with darker glauconitic 
burrows are certainly a lyelli Subzone assemblage. The two specimens (Nos. 4 & 6) 
preserved in glauconitic sandy dark grey clay suggest, however, a high spathi Subzone 
age. It has been suggested above (p. 47) that the type of Anahoplites mimeticus is a 
spathi Subzone species of Hopiites (H.) and certainly did not come from the Carstone, 
of the Isle of Wight. The association of Anahoplites of the osmingtonensis-grimsdalei 
group with species of Hopiites (H.) in the Osmington area of Dorset which Spath 






IN THE ANGLO-PARIS BASIN 57 

(1926b ; 422) considered to be of benettianus Subzone age in fact marks the extreme 
summit of the spathi Subzone (p. 51). This association is also to be seen at the 
summit of the spathi Subzone at Caen Hill, Devizes (p. 60) and probably also at 
Dilton Marsh. 

(ii) VALE OF WARDOUR TO DEVIZES (WILTSHIRE) 

(a) Vale of Wardour 

No sections in Middle Albian sediments are now to be seen in the Vale of Wardour. 
A brickyard was worked throughout much of the 19th Century near Ridge and was 
first described by Fitton (1836 ; 247) and was listed by d'Orbigny (in Geinitz 1849) as 
' Rudge '. Jukes-Browne (1900 ; 230), Reid (1903 ; 32, 39), and Andrews (in Andrews 
et al., 1903 ; 158) provided further information about this section. Fitton's ' Am- 
monites rhotomagensis ' suggests Lyelliceras lyelli indicating the lyelli Subzone but 
the specimen has not been traced. Both Fitton and Jukes-Browne record Inoceramus 
sulcatus as well as /. concentricus from this area and the varicosum Subzone is certainly 
present in marls at the Watercress beds Fovant (Mottram 1957 ; 166, 1961). 

The only other sections are a well at Dinton described by Jukes-Browne & Andrews 
(1891 ; 292 & 1900 ; 228 : and in Reid 1903 ; 31, 38), and an exposure of the basal 
beds in Wardour Park (Reid 1903 ; 34, Mottram 1957 ; 161). Casey demonstrated 
(1956 ; 231, 1961a ; 565) that the lower part of the sequence in the Dinton well was of 
kitchini Subzone (Lower Albian) age and was overlain non-sequentially by clays of 
dentatus Zone age. However, no fossils have been preserved from the clays and it is 
impossible to determine their subzonal position. At the present time it is not possi- 
ble to correlate these three sections with each other, or any section south or north of 
the Vale. 

(b) Maiden Bradley to Devizes 

No sections now exist in this area of the outcrop, although brick pits formerly 
existed at Redford Water, Flintford, Crockerton, and Westbury, all described by 
Jukes-Browne (1900 ; 235-6). From his account of them it is possible to gain some 
idea of the lithological sequence in the lower part of the Gault in this area (text-fig. 25) . 

The Crockerton section was worked in the early part of the 19th Century and 
yielded to Miss Benett the holotypes of Ammonites benettianus and Ammonites 
laevigatas described by J. de. C. Sowerby. It also probably yielded the specimen of 
Ammonites monile mentioned by Fitton (1836 ; 258) and a good deal of the English 
lyelli Subzone ammonites in the various collections used by Spath in his Monograph 
of the Ammonoidea of the Gault. Until the late 1930's it was the only section known 
in England to have exposed sediments definitely containing Lyelliceras lyelli. There 
is now a factory on the site. 

Unfortunately, there are no detailed accounts either of this section or the others 
mentioned above. However, Jukes-Browne's account (text-fig. 25) suggests that 
the sequence is fairly uniform. It appears that ' Division ' 3 definitely yielded lyelli 



5» 



MIDDLE ALBIAN STRATIGRAPHY 



Subzone fossils and by comparison with Caen Hill, Devizes (p. 60), probably was the 
source of some spathi Subzone ammonites also known from Crockerton. 

In the Westbury area, the Eden Vale Brickyard described by Jukes-Browne (1900 ; 
236) is no longer exposed, but the pit worked by the Westbury Potteries Ltd., has 
shown sections of the basal beds of the Gault from time to time. Casey (1956 ; 233 : 
1961a ; 564) has referred to this section as the Bremeridge pit demonstrating the 
presence of the kitchini Subzone overlain non-sequentially by the basal beds of the 
Gault of dentatus Zone age. This pit is presumably the source of the specimen of 
' Anahopiitoides ' from Dilton (Ponsford Colin.) illustrated by Casey (1966 ; 547 
text-fig. 207c). 



REDFORD WATER 



FLINTFORD 



CROCKERTON 



EDEN VALE 



M Ft 
9 -r30 



6 --20 



3--10 



3 




3 


• 

m 

m 

m> 

m 

* 


3 




• 

mi 

m 








*> 




m> « 




1 i 




i_ e 






























1 i 











Fig. 25. Possible correlation of sections in the Warminster area of Wiltshire described by 

Jukes-Browne (1900 ; 235-6). 



(c) Caen Hill, Devizes 

The area W. of Devizes has been a centre of brick and tile production since the 
latter half of the last century. The sections then exposed at Caen Hill and Dunkirk 
were described by Jukes-Browne (1892 : 1900 ; 249-250, 252 : 1905 ; 15-16) and 
Osborne-White (1925 ; 39). Old collections in the British Museum (Nat. Hist.) and 
Institute of Geological Sciences indicate the presence of the Peodentatus, lyelli & 
spathi Subzones in this area, and some of the ammonites were described by Spath 
(1923-1925). 



IN THE ANGLO-PARIS BASIN 



59 



Li th o logy 



Light grey weathered clay with limonttic concretion* otter pyritic ?fossils.j 



Weathered grey clay. 



Pyritic dork grey clay weathering ferruginous. 



Weathered blocky silty micaceous dark grey clay with bleached areas ot 
parting planes. 



(v) Blocky massive grey cloyey silt, weather ing white. The top 12inches 
contains more cloy. 



(iv) Dork grey silty clay with filaments. 



(iil)Grey clayey silt with pyritic filaments; passing at the base into 6(ii). 



(ii) Sparsely shelly glauconitic grey clay with pyritic filaments. 



(i) Very silty micaceous cloy with pyrite a nd l enses of sittstone. 



Poorly bedded massive micaceous silty clay, rather more silty.in the lower 
1 foot 5tnches, with many pyritic filaments, a shell seam occurs 3 feet 
from the base and contains brown phosphatic concretions. The clay ( darkish 
grey in colour, contains scattered shells with a tew large crushed ammon- 
ites in the sediments above the 3 feet level. 



Brownish fawn silty clay, extensively burrowed, with infill i ngs of dark i 

grey clay. w 




(iii) Tough silty glauconitic dark grey clay with a few scattered shells. 



(it) Port-phosphotised ammonites & cementstone nodule s in burrowed cloy. 
(i) Passage bed between lithology of Beds 4 and 5 (iii). 



Fawn silty clay with glauconite-sa nd infilled burrows. 



Finely silty micaceous clay, coppery brown in colour when wet and fresh, 
with patches of dark grey clay. Both are cut by fawn coloured burrow 
infillings in top 8 inches. Pyritic filaments occur throughout; shelly 
especially in the upper part. 



Prominent ond persistant seam of sandy ferruginous marlstone- 



Medium grey clay with some phosphatic nodules. 



Ft Ins M. 



' * ' z z z 



10 »- 
8 



Fig. 26. Section in Gault at Messrs Hills of Swindon Ltd's Caen Hill brickyard, c. 180 
yds ENE. of the Olive Branch Inn, in the W. side of Caen Hill, Rowde, Wiltshire (ST 
98246135). 



60 MIDDLE ALBIAN STRATIGRAPHY 

The presence of the eodentatus Subzone is suggested by Cleoniceras? devisense 
Spath (1923a ; pi. IV, fig. 7a, b) and Hoplites cunningtoni Spath (1923a ; 109, pi. VIII, 
fig. 8a, b). Specimens of Cleoniceras (C.) are known from the eodentatus Subzone in 
France but they are very rare and Mrs. P. Jennings has obtained one undoubted 
lyelli Subzone example from Badbury Wick. Hoplites cunningtoni is a late Otohoplites, 
a genus also known to occur in the eodentatus Subzone elsewhere in southern England 
and in France. The lyelli Subzone is indicated by ammonites such as Beudanticeras 
laevigatum and Hoplites (H.) baylei, and the spathi Subzone sediments are still ex- 
posed. The most important result of the present study is the discovery of a 
reasonably thick sequence of sediments of intermedius Subzone age at Caen Hill. This 
occurrence and that at Didcot (p. 63) represents the first time that the subzone has 
been recorded in this area of the outcrop in Wiltshire and Berkshire. 

Spath (1943 ; 745) followed Osborne-White (1925 ; 39) in considering that the 
lautus Zone was present in the Gault of the Devizes area. This opinion was based 
on material obtained by Cunnington from the long since vanished brickpit at Dun- 
kirk. However, Jukes-Browne (1900 ; 252, 1905 ; 16) lists Inoceramus sulcatus as 
well as /. concentricus and it is quite possible that this indicates the orbignyi Subzone. 
This particular record of the lautus Zone should be treated at this time with caution. 

The brick pit at Caen Hill is still in work. It was formerly owned by the Devizes 
Brick & Tile Co. Ltd., but now by Messrs Hills of Swindon Ltd. It is situated on the 
W. side of Caen Hill and has been worked eastwards into the hill exposing the section 
given in text-fig. 26. A dip of 3 towards the E. is present. The lyelli Subzone 
sediments are seldom exposed now, and no satisfactory section has been seen by the 
writer. It is possible that ' Division ' 4 (text-fig. 25) of the Warminster-Devizes area 
is the same as Bed 2 of my section. If this is the case then the pre-spathi Subzone 
sediments are thick at Caen Hill. 

Beds 1 to 5 contain Hoplites (H.) spp., such as H. (H.) dentatus and H. (H.) 
maritimus, indicating the spathi Subzone together with a good benthonic fauna of 
bivalves and gastropods. A shell seam 3 feet (0-914 m.) above the base of Bed 7 
contains crushed evolute Anahoplites oigrimsdalei type and ribbed forms comparable 
to A . evolutus and A . osmingtonensis together with occasional specimens of Hoplites 
{H.). This association continues through part of the remainder of Bed 7, and these 
sediments are here considered to be a little later than the concretions in the Osming- 
ton area, Dorset (p. 51) which are classified with the uppermost part of the spathi 
Subzone and may be represented at Devizes by Bed 6 and the basal 3 feet of Bed 7. 
However, at Devizes in Bed 7 the situation is reversed, Hoplites (H.) being here sub- 
ordinate to Anahoplites, and so these clays are classified with the basal part of the 
intermedius Subzone. This level is, therefore, closely comparable to the basal part 
of the intermedius Subzone in the Departements of the Meuse (p. 88) and Aube (p. 93). 
In the Weald, this interval does not contain ammonites. 

The remainder of Bed 7, and particularly 8, contains a typical intermedius Subzone 
fauna with crushed Anahoplites praecox and A. intermedius. No fossils were ob- 
tained from Beds 9-1 1 and their subzonal classification is, therefore, unknown at this 
time. 



IN THE ANGLO-PARIS BASIN 61 

(iii) DEVIZES TO THAME (OXON) 

(a) Badbury Wick (Wiltshire) 

There is no information available at the outcrop between Devizes and the Swindon 
area, a distance of about 18 miles (text-fig. 18). Messrs Hill's of Swindon Ltd's pit at 
Badbury Wick has shown a section in spathi Subzone sediments for some years, but 
in 1967 the pit was deepened and exposed sediments of lyelli Subzone age. The 
sequence now exposed is shown in text-fig. 27. Although this is the first time in this 
century that a lyelli Subzone sequence has been well exposed in Wiltshire, it is 
apparently different from that of Caen Hill and further south-west (text-figs. 26 & 25). 
A working near the present pit was mentioned by Ramsey, Aveline & Hull (1858 ; 

33)- 

Beds 1 to 6 contain a typical lyelli Subzone fauna but in contrast to Small Dole 
(p. 38) Lyelliceras lyelli and Brancoceras spp. occur only infrequently and the bulk 
of the fossils are crushed. The commonest ammonites are the heteromorphs such as 
Protanisoceras (P.) barrense and P. (P.) alter notuberculatum together with Beudanticeras 
laevigatum, and Hoplites (H.) spp. The facies is a shelly one, albeit sparsely in places, 
with in general a better developed benthos than that seen in Sussex. Ammonites are 
apparently rare in Bed 6 which otherwise contains very well preserved but fragile 
bivalves and gastropods. That it still belongs to the lyelli Subzone is indicated by 
the occurrence of Beudanticeras spp. as well as Hoplites (H.) spp. 

Beds 7 to 11 are classified with the spathi Subzone. Bed 7 shows the major change 
in the ammonite fauna which marks the base of the spathi Subzone, and these now 
consist of species of Hoplites (H.) such as H. (H.) dentatus and H. (H.) maritimus sp. 
nov. associated with the bivalve Inoceramus concentricus in shell seams. The 
benthonic fauna is very reduced in comparison with the lyelli Subzone sediments 
below. Bed 8 contains the same fauna with individuals partly phosphatised with the 
shell, while in Bed 9 the fossils are again crushed flat. In Beds 10 and 11 the shells 
are replaced by pyrite and the non-ammonite element of the fauna becomes un- 
common. No fossils have been found in Bed 12 and its age is uncertain. 

The lithological sequence in the spathi Subzone is quite different from that of Caen 
Hill, Devizes (text-fig. 26), where there is no pyritic facies in any part of the spathi 
Subzone sequence and a good benthos is present throughout. The sequence at 
Badbury in this Subzone is surprisingly reminiscent of that exposed in the Nyewood- 
Selborne area of the western margin of the Weald (Owen 1963a). However, there, 
the situation is somewhat reversed, the pyritic facies encompassing the sediments up 
to and including the two ferruginous marly bands, the shelly facies prevailing in the 
higher beds. 

(b) Badbury to Thame 

The Gault outcrop in the Vale of White Horse (Berkshire) has been discussed 
principally by Hull & Whitaker (1861), Jukes-Browne (1900 ; 268) and Arkell (1947a ; 
167-9). No sections now exist either at Uffington or in the area N. of Childrey. 
Arkell recorded the discovery of specimens of Dimorphoplites by Mr. C. W. Wright in 



62 



MIDDLE ALBIAN STRATIGRAPHY 



Bed 



12 Micaceous, glauconitic, very clayey burrowed silt. 



Li th ology 



Weathered light-grey pyritic clay with a few shell seams, 
the shells being replaced by pyritic films. 



Ferruginous pyritic m arl, weather i ng rusty, with phosphatic nod's. 



Fawnish-grey slightly micaceous shelly clay. 



Fawn marly clay weathering ferruginous with pa rt-phosphat ised 
fossils and a few phosphotic nodules. The bed is shelly. 



Shelly highly glauconitic dark grey clay with more 
glauconitic silty bands. The clay is micaceous, and pyritic 
filaments occur scattered throughout. Pockets of glauconite 
occur also, together with some burrows infilled with grey 
silt. Although still shelly, the basal 18 inches does not 
contain ammonites and is immediately overlain by a 12inch 
seam of highly glauconitic silty clay. A bedding plane 4 
inches below the top contains pyritised ammonites with their 
shells preserved. 



Dark grey gritty micaceous shelly clay becoming more plastic 
downwards. 



Fawn grey plastic clay, shelly with a few burrows. Scattered 
black septarian phosphatic nodules at top, and a few similar 
ones occur to 1 foot below the top. A few pyritised ammon- 
ites occur scattered throughout, together with large part 
phosphatised ammonites in gritty concretions 4-5 Inches from base 



Tough dark grey gritty clay shelly with large black phosphatic 
nodules at top, 8. scattered septarian phosphatic nodules at base. 



Fawn grey plastic, silty, micaceous, sparsely shelly clay, with 
numerous pyritic filaments and part-phosphat i sed fossils 
at base. 



Brownish fawn shelly clay, burrowed, with dark fa\ 
nfillinqs; passing down into Bed1. 



Dark fawn-grey clay. 



t * W 



Ft Ins M 
— 9 



9- 



8- 



7- 



6-12 
6- 



3 6 
to 

4 



9 V 
6 



Fig. 27. Section in Gault at Messrs Hills of Swindon Ltd's Badbury Brickworks, W. of Day 
House Lane, 200 yds SW. of Badbury Wick House, Chiseldon, Wiltshire (SU 18828160). 



IN THE ANGLO-PARIS BASIN 63 

the Childrey section (1947a ; 169) and I have been kindly allowed to re-examine them. 
They are, as identified by Mr. Wright, a specimen of Dimorphopiites biplicatus 
(C.W.W., 9762) and a specimen of D. glaber (C.W.W., 9761). Together they 
indicate an horizon somewhere between the base of the meandrinus and the top of the 
daviesi Subzones. 

Nine miles ENE. of the Childrey brickyard is the famous section at Culham (Oxon). 
This pit situated approximately 200 yds. N. of the River Thames, 425 yds. E. of the 
road bridge over Culham Cut and 700 yds. SSW. of Culham College, Culham, Oxon 
(SU 51159487) was in work from the middle of the last century until the late 1940*5. 
It has been described by Phillips (i860 ; 548-550, 1871 ; 426-428), Jukes-Browne 
(1900 ; 268-9, 1908 ; 13-14), Osborne-White (1904 ; 300-304), Treacher (1908 ; 
548-550) Pringle (1926 ; 101-2), and Arkell (1947a ; 169-170). Osborne- White's 
account paved the way for the more detailed description given by Pringle, but the 
section is now badly degraded and overgrown and it is not possible to confirm or deny 
Pringle's subzonal grouping repeated by Spath (1943 ; 745-6). Neither is it possible 
to make a direct comparison with the sequence at Badbury Wick. From the list of 
fossils collected by Osborne- White (Jukes-Browne & Osborne-White 1908 ; 14) from 
Bed 3 (= Bed 1 of Pringle 1926) it seemed possible that either the mammillatum Zone 
was present or possibly the eodentatus Subzone. Douvilleiceras does range up into the 
lyelli Subzone but is rare in that Subzone in England except at Shere. Casey, 
who has revised the identification of the ammonites, is in favour of a basal dentatus 
Zone age (1961a ; 565), and it is significant that Osborne-White records ' Hoplites 
interruptus ' just above Bed 2 (1904 ; 304). Beds 2 and 3 of Pringle were classified 
by him with the ' benettianus Subzone ', and Beds 4 and 5 with the spathi Subzone. 
From the ammonites preserved in the various collections it is apparent that both the 
lyelli & spathi Subzones are present. 

It is interesting to note that in the remnant of Gault formerly exposed at the 
abandoned Chawley Brickyard, Hurst Hill (SP 47550420), Cumnor, Pringle (1926 ; 
98, 103) recorded ammonites which he considered to be characteristic of Bed 4 at 
Culham. This section was situated 7 miles NNW. of Culham and has also been 
discussed by Arkell (in Richardson, Arkell & Dines 1946 ; 104). If the equivalents of 
Beds 1 to 3 are truly absent in this outlier, this is of some palaeogeographic significance. 

The only other useful information yielded by this area is provided by two borings, 
Nos 6 and 21, drilled for the new Central Electricity Generating Board Didcot Power 
Station (SU 51289174 & 51339194 respectively). Together, the fragments of these 
two cores show the following features in the sequence. The orbignyi Subzone is in a 
Gault facies, indicated in Boring No. 21 by a fragment of core containing Inoceramus 
sulcatus preserved in mid-grey micaceous silty clay with lighter coloured burrows 
from a height of 122 feet 6 inches (37-34 m.) above the base of the Gault. The 
intermedins Subzone is also present at a height of 68 feet (2073 m.) above the base of 
the Gault in Boring No. 6 where the core yielded a crushed specimen of Anahoplites 
praecox preserved with a pyrite-replaced shell in silty brownish grey clay (cf. Bed 
8 ii at Caen Hill, Devizes, p. 60). Boring No. 21 shows that the spathi Subzone with 
Hoplites (H.) spp. is certainly present in the sequence between 42 feet 6 inches and 
17 feet 6 inches (12-95-5-33 m.) above the base of the Gault. The pieces of core 



64 MIDDLE ALBIAN STRATIGRAPHY 

preserved are from 42 feet 6 inches, 35 feet, 32 feet 6 inches, 30 feet and 22 feet 6 inches 
above the base of the Gault and the lithology consists essentially of dark fawn-grey 
silty clay with shelly fossils. There is no need to emphasise that the cores are very 
incomplete and that no Subzonal limits can be deduced. 

Sections in the Gault were formerly exposed in the area of Thame (Oxon) and 
mentioned by Davies (1899b ; 160). The only information about the zonal strati- 
graphy is the comment by Spath that at Priestend (SP 691055) the lower Gault, 
which was exposed for at least 40 feet (12-16 m.), contained plentiful impressions of 
ammonites of the dentatus Zone often of unusually large size (1943 ; 746). 

(iv) THAME TO LEIGHTON BUZZARD (BEDFORDSHIRE) 

The published information on the stratigraphy of the Gault between Thame and 
Leighton Buzzard, a distance of about 19 miles is again not particularly satisfactory. 
This is due mainly to the paucity of good exposures and, to a certain extent, to the 
controversies which have tended to colour the accounts. It is apparent that deposits 
of Middle Albian age are present throughout the area, although they are greatly 
reduced in thickness in comparison with the alleged sequence at Thame. The 
Gault rests in this area either upon the Kimmeridge Clay, Portland, Purbeck, or 
Lower Greensand deposits. 

(a) Long Crendon (Bucks.) 

No section in the Gault now exists at Long Crendon, which is situated about 2-|- 
miles towards the N W. of Thame, but sections in this outlier were described by Jukes- 
Browne (1900 ; 277), Davies (1899a ; 22), Lamplugh (1922 ; 40-44), and Kitchin & 
Pringle (1922 ; 164-5). The sequence has also been discussed by Kitchin & Pringle 
(1921a ; 62 : 1922 ; 284-5), Spath (1943 ; 746) and Casey (1961a ; 569). Kitchin & 
Pringle (1921a ; 62 : 1921b ; 174 see also Spath 1943 ; 746) considered that the Upper 
Gault rested directly upon Purbeck Beds here but the detailed evidence to sub- 
stantiate this conclusion was not given. 

On three counts it appears certain that Lower Gault is present. It is important 
to note that Davies (1899a ; 22 : 1899b ; 161) recorded /. concentricus from the 8 feet 
of Gault then exposed, but no ammonites were discovered and, therefore, the exact 
age still remains uncertain. In the main outcrop to the S., the lower part of the 
Upper Albian is quite fossiliferous with orbignyi Subzone ammonites and the ubiquit- 
ous Inoceramus sulcatus. Also Lamplugh (1922 ; 40-44) demonstrated that a thin 
development of Shenley Limestone was present below the Gault (see also Casey 
1961a ; 569). It seems probable, therefore, that Davies' record of /. concentricus is 
correct, that these clays are of Middle Albian age, and that there is no overlap of 
Upper Gault in this area as Kitchin & Pringle held. 

(b) Haddenham (Bucks) 

Although no section exists in the main outcrop between Thame and Aylesbury, 
two ammonites are preserved in the Buckinghamshire Country Museum, Aylesbury, 



IN THE ANGLO-PARIS BASIN 



65 



which are labelled Haddenham. Although the circumstantial evidence indicates that 
this is the Buckinghamshire Haddenham, this locality is not on the Gault whereas the 
Cambridgeshire locality is. With this reservation in mind these ammonites (W. J. 
Welford Colin., accession No. 176-24) are here identified as Euhoplites aff. meandrinus 
and Dimorphoplites aff. niobe (the late mutation known from the upper nodule bed 
of Bed IV at Folkestone). Both are preserved as incomplete blackish phosphatic 
casts without the shell, and indicate a distinct nodule bed or clays with scattered 
nodules of late loricatus Zone age within the Gault of this area. 

Davies (1899a ; 55-56) disputes that the Gault was exploited S. of Haddenham 
Low situated about i\ miles NE. of Haddenham (See also Balance 1964 ; Map 2). 
The main outcrop, however, is at no great distance to the E. of Haddenham. No 
information has been published about Middle Albian sediments in the 6 mile tract 
of country between Haddenham and Aylesbury, although Balance (1964 ; 396) has 
reported the Lower Gault to be present throughout the area. 

(c) Aylesbury (Bucks) 

The basal part of the Gault was formerly exposed in the Walton Cutting on the 
Metropolitan railway line (L.T.E.). The cutting extends SSE. from the bridge 
(SP 823130) carrying the B 4443 (Stoke Road) over the railway line, Walton, 
Aylesbury. It was described by Pringle & Chatwin {in Sherlock 1922 ; 9) who 
reported that the basal bed of the Gault rests directly upon the Portland Beds. No 



Bed 



Li t h o I og y 



Mottled fawn shelly clay marked by a shell seam at the 
base with part phosphat ised fossils. 



Dark grey shelly clay with scattered phosphatic nodules 
becoming glauconitlc and gritty downwards In basal 10 inches I 
the sediment has become very glauconltic and gritty in current i 
swirls of glauconlte sand. 



Scattered black septarian phosphatic nodules in qlauconitic clay. 



Weathered grey glauconitlc clay. 



At 

■A 



Whitish phosphatic nodules with a few black septarian phosphates^ 



Glauconitlc gritty loam brownish in basal 1 foot with scattered i 5 
brown phosphatic nodules. c 



Ferruginous yellow gritty clay resting on guttered surface of:- 
Portland Beds 



Ins M 



10 



2 

2 north 



6 south 



2 1-1 
4-5 
2-3 



Fig. 28. Section exposed in trench dug by Messrs S. A. Leach & Co. along the field bound- 
ary extending for about 150 yds from SP 8235012425 to SP 8245012333, approximately 
midway between the B 4443 Stoke Mandeville road and the L.T.E. Metropolitan railway 
line from Aylesbury to Stoke Mandeville, Aylesbury, Buckinghamshire. 



66 MIDDLE ALBIAN STRATIGRAPHY 

fossils were found, and indeed, the only fossils recorded from the lower part of the 
Gault in this area were obtained from a nodule bed stated to occur at about 10 feet 
(3-04 m.) above the base of the formation (Pringle & Chatwin in Sherlock 1922 ; 9). 
This bed has yielded an upper Albian fauna (Jukes-Browne 1900 ; 278 whose inclusion 
of tins horizon in the Lower Gault was an error : C. W., & E. V. Wright 1939 ; 115- 
116 : Spath 1943 ; 746). Kitchin & Pringle took this fact to confirm an extreme 
conclusion, stating that the Lower Gault had been overstepped by the Upper Gault 
in this area (1922 ; 164-5). Pringle & Chatwin (in Sherlock 1922 ; 8) were more 
objective in that they pointed out that there was no evidence at that time for the 
presence of the Lower Gault. Spath (1943 ; 746) although vague was a little more 
cautious. 

Important new information, demonstrating the presence of the spathi Subzone in 
the lower beds of the Gault, was obtained by the writer from a trench dug by Messrs. 
S. A. Leach & Co., during the laying of sewer pipes in January 1967. This very 
temporary section was situated only a few hundred yards S. of the Walton Cutting 
and the sequence is shown graphically in text-fig. 28. 

No fossils were obtained from Beds 1-5 and their exact age is uncertain. Bed 6 
yielded a small bivalve fauna consisting mainly of a small Ostrea and a few specimens 
of Nucula together with a single example of Neohibolites minimus. The shell seam 
at the base of bed 7 contains numerous Inoceramus concentricus and some partly- 
phosphatised Hoplites (H.) with simple dentatus ribbing, all with the nacreous shell. 
The species include H. (H.) dentatus and H. (H.) cf . maritimus some being quite large 
— 6 to 8 inches in diameter, and the specimens of I. concentricus are also of large size. 
A few specimens of Dentalium and Nucula also occur. This same faunal assemblage 
occurs in the remainder of Bed 7 but it is crushed flat. The ammonites indicate the 
lower part of the spathi Subzone, and it is unfortunate that no higher levels were 
exposed at this locality. 

Another ' cut and fill ' trench exposing higher beds was excavated in February 
1967 in the area approximately 1475 yds a little S. of E. of the trench described 
above. This trench was dug to a depth of 6 feet and extended from a point about 
600 yds NNE. of Stoke Grange to a point about 400 yds. ENE. of Stoke Grange 
(SP 8357512340 to SP 83801 190), to the NE. of the A 413 (Wendover Road), Ayles- 
bury. The trench was apparently cut in the direction of strike and exposed weathered 
dark blue-grey clay with small buffish phosphatic nodules and patches. No 
determinable fossils were found except at the field boundary (SP 83621225) where 
two very badly preserved fragments of ammonites were seen. One was comparable 
to Dimorphoplites, the other an equally poor fragment of Euhoplites. Together they 
suggest an horizon below that exposed in the trenches along the A 41 in the Aston 
Clinton area described by Wright & Wright (1939) which at certain points yielded an 
orbignyi Subzone fauna. 

There is no doubt that the thickness of sediments below the orbignyi Subzone 
nodule bed in the Aylesbury area exceeds 10 feet (3-04 m.) and it is likely that there 
is a good deal more. 



IN THE ANGLO-PARIS BASIN 



67 



LITTLEWORTH 



M Ft 



►25 



7- 



6- "20 



5- 



AYLESBURY 



-15 



4- 





SOUTHCOTT 



/ 



Klmmaricfga 
Clay 



Woburn 
Sands 



BILLINGTON 
CROSSING 




Fig. 29. Correlation of sections between Aylesbury and Leighton Buzzard. 



68 MIDDLE ALBIAN STRATIGRAPHY 

(d) Aylesbury to Leighton Buzzard (Beds.) 

At the outcrop between Aylesbury and Leighton Buzzard, a distance of about 10 
miles, there is very little information about the stratigraphy of the Gault except for 
borehole records e.g. Jukes-Browne (1900). A brickyard at Littleworth (SP 881233), 
Wing, Buckinghamshire, described by Jukes-Browne (1900 ; 278), Davies (1901 ; 140, 
1915 ; 92) and Lamplugh (1922 ; 89-90), is now badly degraded, Lamplugh (1922 ; 40) 
records Inoceramus concentricus from the ' 10 to 15 feet of shattery dark-blue 
Gault . . . ' which was estimated to lie at about 10-12 feet (3-04-3-65 m.) above 
the Gault basement bed. Specimens from the Lamplugh Collection are preserved 
in the British Museum (Nat. Hist.) (BMNH L 59863-8) and indicate that these 
sediments are of Middle Albian age. There is, therefore, over 27 feet (8-22 m.) of 
Middle Albian sediments in this area resting upon a thin development of Shenley 
Limestone which in turn rests upon Kimmeridge Clay. It is significant that Neo- 
hibolites minimus is apparently plentiful here, in contrast to the Aylesbury area. 

In the short distance (1^ miles) between Littleworth and Southcott, Buckingham- 
shire (SP 90052452), the Woburn (or Leighton) Sands intervenes below a similar 
development of Shenley Limestone (Lamplugh 1922 ; 38). Moreover, the Shenley 
Limestone lenticle forms the base of a 2 to 3 foot bed of loam with phosphatic nodules 
below the Gault. These phosphatic nodule beds form an important feature at the 
base of the Gault at Leighton Buzzard, Bedfordshire, where they are essentially of 
late tardefurcata and early mammillatum Zone age, with the eodentatus Subzone of 
the Middle Albian at the top. The equivalent of the Lower Gault represents the 
spathi, intermedins, and niobe Subzones. A description of the Albian sediments in 
the Leighton Buzzard area is to be presented elsewhere, and at a later date, an account 
of the Middle and Upper Albian sediments of East Anglia will also be given. This 
region flanking the London platform and the North Sea area, although of considerable 
stratigraphical interest, does not contribute any fundamentally new knowledge to the 
ammonite zonal sequence of the Anglo-Paris Basin, the stabilization of which is the 
main purpose of this paper. 



E. Borehole Evidence 

There are now a great number of deep boreholes in southern and eastern England 
drilled principally in the search for water, oil and gas, and in Kent, for coal. To this 
number can be added a few purely exploratory borings. These have provided a good 
picture of the post Tertiary configuration of the Palaeozoic surface, and of the strati- 
graphy of the Mesozoic sediments which have buried it (e.g. Kent 1949, Falcon & 
Kent i960). It is now apparent that Albian sediments underlie the Chalk through- 
out the area covered by that formation in England. In this work, the Wessex basin, 
and the area of the London Basin, Essex, and East Kent only will be considered. 
Borings in these areas have yielded important new information, including strong 
indications of post Jurassic to basal Upper Albian faulting along part of the Thames 
axes, certainly E. of London (Owen, in press) . 






IN THE ANGLO-PARIS BASIN 69 

(i) HAMPSHIRE BASIN 

(a) Winchester District 

The only borings through the Gault which have yielded information of zonal value 
are situated in the Winchester area and were drilled for the Gas Council by the British 
Petroleum Co. 

Winchester No. i Chilcomb, Hants. (SU 50172830) 

The division between the Upper Greensand and Gault is taken at a depth of 
310 feet (94.48 m.) and the Gault is 250 feet (76-2 m.) thick. Coring was not con- 
tinuous and neither the thickness of Upper Albian sediments nor the exact Subzonal 
boundaries in the Middle Albian sediments could be determined. Nonetheless, the 
fragments of core show that between 426 feet 6 inches and 438 feet (128-16 m.- 
133-50 m.) the essentially dark-grey silty and shelly micaceous clays contain 
Inoceramus sulcatus indicating a lower Upper Albian age (cristatum or orbignyi Sub- 
zones). There is then a gap of 41 feet (12-49 m -) m cored samples. 

At 479 feet (146 m.) depth, the mid-grey shelly silty micaceous clays are of Middle 
Albian, intermedins Subzone age, and the sequence contains Anahoplites of the 
intermedins group to a depth of 490 feet 2 inches (149-40 m.), a level 69 feet 10 inches 
(21-28 m.) above the base of the Gault. The spathi Subzone with crushed Hopiites 
(H.) spp. is certainly present at a depth of 501 feet 1 inch (152-73 m.), and the sedi- 
ments from this level to a depth of at least 513 feet 3 inches (156-43 m.) consist of 
alternating fawn and mid-grey, silty micaceous shelly clay bands. At 521 feet 
(158-80 m.) the nacreous shells are found to be completely replaced by pyritic films, 
and this pyritic facies is a feature of the sequence down to the base of the Gault at 
560 feet (160-68 m.). Crushed Hopiites (H.) spp., are present in the predominantly 
fawn-grey silty micaceous clay of the lower part of the Gault to a depth of 526 feet 
(160-32 m.) but no ammonites have been found in the remaining 34 feet (10-36 m.). 
The basal 5 feet (1-52 m.) of the Gault is very pebbly, becoming a pebbly loam at 
559 feet (170-38 m.) depth. The Lower greensand underlies the Gault. 

Winchester No. 4 Itchen Valley, Hants. (SU 51133001) 

This boring produced only poor chip and core returns during its traverse of the 
Gault. Hopiites (H.) sp. with dentatus ribbing was found at 11 feet 6 inches (3-50 m.) 
above the base of the Gault, at a depth of 1258 feet 6 inches (383-43 m.). This was 
preserved in an identical manner and lithology to that seen at the same level in 
Winchester No. 1. 

Winchester No. 5 Twyford, Hants. (SU 50252712) 

Only a few cored samples were recovered from the chipped sequence. At a depth 
of 963 feet 8 inches (293-52 m.) only 7 feet 4 inches (2-235 m -) above the base of the 
Gault, a crushed heteromorph ammonite with indications of lateral spines was found. 
This is almost certainly a Protanisoceras (P.) and indicates the lyelli Subzone. 



7 o MIDDLE ALBIAN STRATIGRAPHY 

(b) Relationship of Winchester to Portsdown, the Weald, and the Isle 

of Wight 

The correlation of the Gault sequence in the Winchester No. i boring with those of 
Selborne, Nyewood, and Compton Bay, is shown as far as is possible in text-fig. 30. 
The lithological succession shown by the Winchester borings is comparable to that of 
the outcrop at Selborne on the western border of the Weald. They both show in the 
spathi Subzone sediments a lower pyritic facies overlain by clays in which the shells 
are preserved and in which a good benthos is present (Owen 1963a ; 43-44). More- 
over, at Bradshott Hall clays of basal Upper Albian age were seen by Osborne- White 
(1910 ; 20) to overlie clays classified with the ' interruptus Zone ' in Jukes-Browne's 
sense. The lower clays could be of intermedins Subzone age (Owen 1963a ; 51). 

From the map given in text-fig. 18, it is apparent that the borings at Winchester 
and Portsdown, and the natural exposure at Culver Cliff in the Isle of Wight all lie 
roughly on the same NNW-SSE. line. The total thickness of the Gault at Win- 
chester No. 1 is 250 feet (76-2 m.) compared with 163 feet (49-68 m.) at Portsdown 
situated 15 miles to the SSE., and just over 100 feet (30-4 m.) at Culver Cliff. No 
information on the degree of ammonite subzonal representation in the chipped 
sequence of the British Petroleum Portsdown boring in known (Taitt & Kent 1958), 
but, in Hampshire, West Sussex, and in the Isle of Wight, there is a similar change in 
facies within the spathi Subzone from pyritic clays below to shelly clays above. 
Superficially it seems that as one proceeds SSE. from Winchester the decreasing 
thickness of the sediments suggests the shallowing of a basin in this direction. How- 
ever, at Winchester the lower part of the Upper Albian is represented by at least 
128 feet (39-01 m.) of silty Gault, more than the total thickness of the Gault at 
Culver Cliff in which the lower part of the Upper Albian is also represented (p. 43). 
The decrease in thickness of Middle Albian sediments from Winchester to Culver 
Cliff is, therefore, not particularly well marked. It is also apparent that the detailed 
lithological sequence in the spathi Subzone sediments which is recognisable for a 
distance of over 35 miles at the outcrop in the south western part of the Weald is 
totally different from that of the Isle of Wight (text-fig. 30). The common distri- 
bution of the pyritic facies reflects the presence of a common sea environment 
which affected different depositional areas, and it is apparent from the pre-Albian 
sequence at Portsdown that this area formed a ridge separating the area of the south 
western Weald from that of the Isle of Wight. 

The Lower Greensand in the south-western area of the Weald thins rapidly towards 
Portsdown (Falcon & Kent i960). Continuing SW. into the Isle of Wight the Lower 
Greensand as a whole thickens from Redcliff NE. of Sandown to reach a known 
maximum in the southern part of the Island and this increase in thickness can be 
correlated with an increase in finer grade sediments. It is apparent from the dis- 
tribution of lyelli and spathi Subzone sediments that the Portsdown ridge affected 
Middle Albian sedimentation. By Middle Albian times this submarine feature con- 
sisted of an elongated swell (text-fig. 52), and its extent can be determined by the 
presence of the ' Iron Grit ' beneath the Gault and the absence of tardefurcata and 
mammillatum Zone phosphatic nodule beds. The Lyelli Subzone sediments are 



COMPTON 
BAY 
M Ft 
"140 



IN THE ANGLO-PARIS BASIN 

WINCHESTER SELBORNE 

NO. 1 



71 



NYEWOOD 



40-.. 



35- 



30- 



■90 



25" 



20- 



15 



10 



5- 



130 



125 



110 



■100 



80 



70 



-60 



.-50 



-40 



30 



20 



10 




s helly 
pyrlllc 



1 'yeltj ? 



g eodentatus ? 



intermtdiui 




Subzonal correlation lines 
Lithological correlation lines 



Fig. 30. Provisional comparison of the Winchester No. 1 boring with the outcrop to the 

south and east. 



72 MIDDLE ALBIAN STRATIGRAPHY 

probably present at Winchester, and may well be present in the unexposed lowest 
part of the Gault at Selborne in the western Weald in view of the close similarity 
which exists in the detailed lithological sequence between this locality and the Horton 
Clay pit, Upper Beeding (text-fig. 14). Sediments of this Subzone are known to 
intervene between the ' Iron Grit ' and the spathi Subzone sediments along the out- 
crop between Nyewood and Storrington, but they are thin and gritty (p. 34). In the 
southern part of the Isle of Wight, however, sediments of this age are again compar- 
atively well developed. The spathi Subzone sequence recognised at Selborne thins 
southwards to Nyewood but lithologically it remains the same (Owen 1963a & text- 
fig. 30). In the Isle of Wight, however, the sediment sequence is quite different. In 
the absence of sections it is not possible at this time to determine whether the Ports- 
down swell affected deposition during later Middle Albian Subzones. 

It is becoming apparent that the thinning of the Lower Greensand and the Gault 
at Compton Bay relates to yet another ' swell ', probably that indicated by the 
Ringwood gravity high, evidence of which is provided by the British Petroleum Co., 
borings at Fordingbridge, Hants (Falcon & Kent i960 ; 48-49), and Bere Regis, 
Dorset (Falcon & Kent i960 ; 7), in which the Gault was found to rest directly upon 
the Kimmeridge and Oxford Clays respectively. 



(ii) LONDON BASIN, EAST ANGLIA, AND KENT 
(a) London Basin, S. Essex & N. Kent 

Borings north of the Thames at Canvey Island (Smart, Sabine & Bullerwell et al., 
1964) Fobbing (Dewey et al., 1925) Beckton Gasworks No. 4 (Barrow & Wills 1913), 
Essex ; Tottenham Court Road (Prestwich 1878, Judd 1884), Willesden No. 1 (Falcon 
& Kent i960 ; 15), London ; and Bushey, Hertfordshire, provide evidence that the 
Upper Gault rests directly upon either the Palaeozoic rocks of the Mesozoic floor or 
upon a thin development of Jurassic or Lower Greensand sediments. However, in 
the Gas Council Cliffe group of borings encompassing the area of the East Tilbury 
Marshes, Essex, and across the Thames in the Cliffe and Higham parishes of Kent, 
Middle Albian sediments are represented in a sequence closely comparable to that 
seen in the Lower Gault of the Maidstone By-Pass (p. 18), and, moreover, they show 
no sign of either a land area or submarine cliff only a few miles to the north. 

The Lower Gault of the Cliffe group of borings rests upon a thin development of 
Lower Greensand which in turn rests upon Oxford Clay preserved in a late Jurassic- 
early Cretaceous graben structure, or in the case of the two most southerly borings 
upon Devonian sediments as at Canvey Island and Fobbing situated to the north of 
the graben. The stratigraphy of these borings, the structure of the area, and its 
tectonic history, are discussed more fully elsewhere (Owen in press) . In this work it 
is concluded that the absence of Lower Gault over much of the area north of the 
Thames in London and South Essex, is due to a further movement of the northern 
fault of this graben in early Upper Albian times. 

Further west in northern Surrey, three borings have yielded information about 
Middle Albian sediments. These are located at Addington, Richmond and Egham 



IN THE ANGLO-PARIS BASIN 73 

(Virginia Water), but the information is very incomplete, and in the case of the last 
boring mentioned it is highly suspect. The location of the borings is shown in 
text-fig. 1. 

Addington 

The boring at the Croydon Waterworks, Addington Pumping Station on the E. 
side of Featherbed Lane (TQ 371628) yielded a core, parts of which are preserved in 
the Institute of Geological Sciences. The Upper Gault-Lower Gault junction con- 
sists of a phosphatic nodule bed with cristatum Subzone fossils and was reached at 
about 879 feet (267-91 m.) depth. This is underlain by grey shelly clay represented 
by fragments of core from between 880 and 882 feet (268-22-268-83 m.) and which 
yield Inoceramus concentricus and poorly preserved ammonites which could indicate 
either a loricatus or lautus Zone age. No further core fragments have survived from 
the remainder of the Lower Gault sequence which has a total thickness of 22 feet 
(6-70 m.). This boring is situated 9 \ miles WNW. of the section at Dunton Green at 
the outcrop (p. 26) and indicates that the thin development of Lower Gault there 
continues along the WNW. direction. 

Richmond 

The boring at the old Richmond Vestry Waterworks, Water Lane, Richmond 
(TQ 17657470) was first described by Judd and Homersham (in Judd 1884) and 
subsequently by Whitaker (1889 ; 214-217). Spath (1926a ; 151, 1930a ; 294) 
demonstrated the presence of the Euhoplites inornatus band at the base of the orbignyi 
Subzone (Upper Gault) and that the Lower Gault is also present. 

The Gault core was stored in the British Museum (Nat. Hist.) for many years before 
being transferred to the Institute of Geological Sciences and is, unfortunately, in a 
dirty state. /. sulcatus is still present at a depth of 1116 feet (340-15 m.), and by 
1119 feet (341-07 m.) /. concentricus is present. The Upper Gault-Lower Gault 
junction occurs, therefore, between these two depths. The base of the Gault was 
located at a depth of 1139 feet 6 inches (347-16 m.) and so the Lower Gault is between 
20 feet 6 inches (6-25 m.) and 23 feet 6 inches (7-16 m.) thick. No subzonally 
diagnostic ammonites are present in the Lower Gault core. The base of the Gault 
rests upon 10 feet (3-04 m.) of sediments tentatively classified with the Lower Green- 
sand which in turn rests upon Jurassic sediments. In the Griffin Brewery boring at 
The Mall, Chiswick, 3^ miles to the NE. of the Richmond boring, the Gault rests 
directly upon Devonian sediments of the London Platform. The age of the base of 
the Gault at Chiswick is, however, unknown. 

Egham (Virginia Water) 

This boring situated at the Holloway Sanatorium, Egham (TQ 002685), was 
described by Dewey (in Dewey et al., 1925 ; 128). He records a band crowded with 
/. sulcatus between depths of 1358-1360 feet (415-91-414-52 m.) some 67 feet (20-42 m.) 
above the base of the Gault. From the basal nodule beds, Templeman collected 
ammonites which led Chatwin to conclude (in Dewey et al., 1925 ; 130, 132) that the 
base of the Gault was of Upper Gault age providing another example of overlap. 



74 MIDDLE ALBIAN STRATIGRAPHY 

Now, Inoceramus sulcatus is characteristic of and restricted to the orbignyi and 
cristatum Subzones and yet the ammonites recorded from the nodule bed at 1424 
feet (434-03 m.) depth include material of varicosum Subzone age. 

A re-examination of the material stated to have come from this nodule bed shows 
that it includes ammonites from various Upper Gault horizons. The specimen of 
Prohysteroceras (GSM. AT 3787) is indeed correctly identified. It is, however, a form 
of the varicosum Subzone preserved in an identical manner to those of the basal 
varicosum nodule bed in the Leighton Buzzard area indicating a southerly extension 
of that bed. As it was found below the lowest recorded occurrence of /. sulcatus at 
1400 feet (42672 m.) depth, the only possible explanation is that it must have fallen 
from the side of the hole together with the other phosphatic fragments during the 
collapse of the hole reported by Dewey (in Treacher & Dewey 1925 ; 450). 

Material acquired later from Templeman is preserved in the Palaeontology Depart- 
ment of the Institute of Geological Sciences and shows that the Lower Gault under- 
lain by mammillatum Zone sediments was in fact traversed by this boring. These 
specimens, unfortunately, have no depth measurements recorded against them, but 
include Euhoplites cf. opalinus (GSM. AT 4800) indicating the lautus Zone ; Euhoplites 
of the meandrinus group (GSM. AT 4799) indicating the upper part of the loricatus 
Zone ; and spathi Subzone Hoplites (H.) spp. (GSM. AT 4801-4) preserved in pebbly 
gritty greyish phosphate. 

Unfortunately, this boring is now stratigraphically suspect, but if one disregards 
the so-called phosphatic nodule bed at 1424 feet depth then it is possible to reinterpret 
the lower part of the hole. The last record of Inoceramus sulcatus was at 1400 feet 
(42672 m.) depth about 27 feet (8-23 m.) above the base of the Gault. This figure of 
27 feet is not an unreasonable one for the Lower Gault when one considers the 
geographical position of the boring. The highest record of /. sulcatus is at 1358 feet 
(413-91 m.) boring depth which indicates that the combined thickness of the cristatum 
and orbignyi Subzone sediments is at least 42 feet (12-80 m.) thick. This is a thick, 
but not impossibly thick, sequence. 

(b) The area of the Kent Coalfield 

Despite the large number of borings and various colliery shafts which penetrated 
through the Gault in the search for Coal Measures in Kent, only a small fraction has 
yielded information on the stratigraphy of the Gault. Financial costs dictated that 
boring through the Mesozoic rocks should be as rapid as possible and the sequence 
was often chipped. However, at the following seven localities shown on text-fig. 31, 
useful information has come to light and it is apparent that eodentatus and lyelli 
Subzones sediments are of widespread occurrence. 

Chislet Colliery 

In the downcast shaft of the Chislet Colliery situated 3020 yds N. 54 30'E. of the 
North Shaft (TR 232657) an exposure of approximately 12 feet (3-65 m.) was seen 
of Lower Gault resting on the basal conglomerate of mammillatum Zone age which in 
turn rests unconformably on Coal Measures (Casey 1961a ; 535). A phosphatised 



IN THE ANGLO-PARIS BASIN 



75 



fragment of Hoplites (Isohoplites) sp. (GSM. Ca 1416) was obtained by Dr. R. Casey 
from 1 foot 6 inches (0-457 m -) above the basal conglomerate indicating the eodentatus 
Subzone. From 2-4 feet (0-60-1-21 m.) above the conglomerate there occur glau- 
conitic gritty darkish grey clays with fossils in which the shells have been replaced 
by pyrite. Ammonites from this bed collected by Dr. Casey include Lyelliceras cf. 
lyelli (GSM. Ca 1423-4) and Hoplites (H.) spp. including H. (H.) baylei (GSM. Ca 
1426), and Beudanticeras cf. albense (GSM. Ca 1431). A specimen of Protanisoceras 
(P.) cf. barrense (GSM. Ca 1437) preserved in the same manner was picked up from 
the tip. This assemblage indicates the lyelli Subzone. One specimen (GSM. Zn 
2472) is a Hoplites (H.) sp. preserved partly phosphatised in mid-grey shelly clay and 
is stated to have come from a height of about 12 feet (3-65 m.) above the basal con- 
glomerate ; it indicates the spathi Subzone. 




suit \_irj •»„ _i_i 



Low«r Gracnsand 



Fig. 31. Locality map of borings yielding subzonal information in the Kent coalfield. 



Ebbsfleet 

Fragments of the core preserved in the Institute of Geological Sciences from this 
boring, situated 495 yds S. 5°E. of Ebbsfleet House, Eastry (TR 337619), about 7$ 
miles E. of the Chislet Colliery, shows that the Lower Gault was entered at between 
depths of 977 and 978 feet (297-79-298-1 m.) and is about 27 feet thick (8-23 m.) 
(Lamplugh, Kitchin & Pringle 1923 ; 178). Loricatus Zone sediments are definitely 
present at 12 feet 6 inches (3-81 m.) above the base of the Gault (GSM., PI. 3854), and 



76 MIDDLE ALBIAN STRATIGRAPHY 

at 7 feet 6 inches to 7 feet (2-286 to 2-133 m.) above the base crushed Hoplites (H.) spp., 
occur with the shell, indicating the spathi Subzone. 

Tilmanstone 

The original manuscript accounts of the succession shown in the Shafts Nos. 1, 2 
and 3 of the Tilmanstone Colliery are preserved in the Institute of Geological 
Sciences. The collecting was carried out by Burr and Griffiths. Griffiths, then 
employed as the Survey fossil collector, knew the stratigraphical value of Inoceramus 
sulcatus and /. concentricus and it is possible to state with some confidence from the 
Log that the junction between the Upper and Lower Gault occurs at a depth of 870 
feet (265-17 m.) in the No. 1 Shaft (TR 288505) and that the Lower Gault is 62 feet 
4 inches (18-99 m -) thick. From the account of the No. 2 Shaft (TR 288504), how- 
ever, the Lower Gault appears to be only about 52 feet (15-85 m.) thick. The 
possible explanation of this difference in thickness is provided by the No. 3 Shaft 
(TR 288505) which showed the Gault to be affected by faulting. Whether this 
faulting is a posthumous movement of the Tilmanstone Fault which affects the 
Palaeozoic rocks and earlier Mesozoic rocks is not clear. Nonetheless, it is readily 
apparent that the Lower Gault at the Tilmanstone Colliery is very thick. Very little 
material has been preserved from these shafts but one specimen (GSM. Zm 5153) is of 
considerable interest. It is an early form of Lyelliceras known to occur in the 
eodentatus Subzone in France, but unfortunately no depth has been recorded against 
the specimen. It is interesting to note that in No. 2 shaft at a height of 21 feet 8 inches 
(6-6o m.) from the basal conglomerate a ' 3 inch band of Ammonites interruptus ' was 
recorded. This might indicate a considerable expansion of the dentatus Zone sediments 
in this area. Further evidence of this is provided by the material from the Shaft of 
the old Guilford Colliery (TR 281469) 2\ miles SSW. of Tilmanstone. 

Guilford Colliery 

The shaft of the Guilford Colliery, situated near the south-western end of Walder- 
share Park, Coldred (TR 281469) is now disused. Fossils collected from the Gault 
during the sinking of the shaft are preserved in the Institute of Geological Sciences 
(presented by the Kent County Education Authority), and in the collection of 
Brigadier G. Bomford to whom I am particularly indebted for permitting me to 
examine his material. Unfortunately, the depths indicated for the individual 
specimens presented by the Kent County Education Authority is suspect. It seems, 
however, that at about 851 feet (259-38 m.) depth, the lautus Zone nodule bed at the 
top of the Lower Gault was reached. This contains material of daviesi Subzone age 
as well as of cristatum Subzone age, and is, therefore, comparable to the nodule bed 
at the outcrop to the west. If this depth of 851 feet (259-38 m.) is correct then the 
Lower Gault is 59 feet (17.98 m.) thick, a little thinner than the No. 1 shaft at 
Tilmanstone. 

The only definite information about the Lower Gault here is provided by Brigadier 
Bomford's collection made from the tip heap of the shaft. This includes material 
from a nodule bed of lyelli Subzone age which yielded Lyelliceras lyelli (GB. 5443, 
5447, 5446), L. radenaci (Pervinquiere) (GB. 5445), Protanisoceras (P.) buvignieri (GB. 



IN THE ANGLO-PARIS BASIN 77 

5465), together with species of Hoplites (H.) of both the lyelli and spathi Subzones. 
This dentatus Zone sequence in the central area of the Kent Coalfield thins consider- 
ably in a south westerly direction towards the outcrop, and there is evidence to 
suggest that it thins also eastwards towards the Kent coast. 

Ringwould 

The Mesozoic rocks traversed by the boring for the National Coal Board made in 
1955 and situated 760 yds W. i4°S. of St. Nicholas's Church, Ringwould (TR 
35294812), has been described by Bisson (in Bisson et al., 1967 ; 111-114), and fossils 
from the Gault were identified by Casey. The Upper-Lower Gault junction consists 
of a phosphatic nodule bed and was met at a depth of 839 feet 4 inches (255-83 m.). 
The top of the tough phosphatic rock bed of the type seen elsewhere at the base of the 
Gault was reached at a depth of 876 feet 11 inches (267-28 m.). The Lower Gault, 
therefore, has thinned to 37 feet 3 inches (11-35 m -) an d the basal few inches in fact 
may well be of mammillatum Zone age. A re-examination of the fragments of the 
core preserved in the Institute of Geological Sciences has yielded the following 
additional information. 

Crushed Dimorphopiites comparable to D. tethydis Spath non Bayle occur at depths 
of 842 feet 3 inches (256-71 m.) and 845 feet 1 inch (257-58 m.) and indicate either the 
top of the meandrinus Subzone, or the lautus Zone. At 860 feet 5 inches (262-25 m.), 
a specimen of Hamites tenuicostatus together with a juvenile ? Dimorphopiites niobe 
at 862 feet 2 inches (262-79 m.) suggest the presence of the niobe Subzone. The 
intermedins Subzone is certainly represented at 866 feet 8 inches (264-16 m.) and 
867 feet 9 inches (264-49 m.) by crushed examples of Anahoplites intermedins. The 
presence of the spathi Subzone is indicated by crushed specimens of Hoplites (H.) at 
871 feet 11 inches (265-76 m.) to 872 feet 1 inch (265-82 m.) in dark grey clay. At 
873 feet (265*25 m.) the clays become glauconitic, and at 875 feet 10 inches (266-95 m.) 
they become sandy for the remaining 1 foot 1 inch (0-33 m.) before the basal rock bed 
is reached. 

The sequence in the lower part of the Middle Albian sediments is demonstrably 
thinner than at Tilmanstone where ' dark sandy Gault ' commences some 21 feet 
(6-4 m.) above the base. An even thinner sequence may be present in the next 
boring mentioned here. 

St. Margaret's Bay. 

The National Coal Board boring at St. Margaret's Bay situated 1030 yds E. 30°N. 
of St. Margaret's Church, St. Margaret's at Cliffe (TR 36654533), has been described 
by Bisson and Melville (in Bisson et al., 1967 ; 105-110). The bulk of the sequence 
was chipped, but at a depth of 800 feet (243-84 m.) cores were taken for 2 feet 
(o-6i m.), at 830 feet (252-98 m.) a 1 foot (0-30 m.) core was taken, and a 3 feet 8 inch 
(1-12 m.) core from 840 feet (256-03 m.) and the base of the Gault at 843 feet 8 inches 
(257-15 m.). The only ammonite recorded was a specimen of a mortoniceratid 
ammonite, probably Prohysteroceras, said to have come from a depth of 830 feet 
(252-98 m.). What is probably a portion of the same ammonite is stated to have 
come from a depth of 830 feet 3 inches (253-05 m.). Casey considers that its position 



78 MIDDLE ALBIAN STRATIGRAPHY 

only 13 feet 8 inches (4-16 m.) above the base of the Gault is anomalous and should 
not be accepted. However, the portion from 830 feet 3 inches (253-05 m.) is not 
apparently derived and even if the specimen had come from the core between 800-802 
feet (243-84 m.) this still suggests a thinner Lower Gault sequence than at Ringwould. 
These records need to be verified in any future boring in this area, but the possibility 
of early Upper Albian faulting here of the type seen in the region of the Thames E. of 
London should not be excluded (Owen in press). The Gault as a whole on the 
E. coast of Kent thins considerably northwards. In the Segas Deal Gas Works boring 
(TR 374533) it is 86 feet (26-21 m.) thick and in the Thanet Water Board Well, 
Margate (TR 365701), it is only 67 feet 6 inches (20-57 m.) thick. 

Aycliff 

The increased thickness of the Lower Gault seen in the Tilmanstone and Guilford 
Collieries is maintained in the Dover area. Lamplugh & Kitchin (1911 ; 8) considered 
from an examination of the Dover Colliery shafts that this was due to an expansion 
of the higher beds of the Lower Gault, but the exploratory borings in the Dover area 
for the Channel Tunnel show in fact that the reverse is the case. There are phosphatic 
nodule beds in the cristatum Subzone comparable to those at Folkestone within 
Bed VIII. The Gault in one of these borings, Dover No. 1 (Aycliff) (TR 294395), has 
been described lithologically by Bisson {in Smart, Bisson & Worssam 1966 ; 101), and 
the Lower Gault sequence is shown in text-fig. 32. 

The lautus Zone is indicated in Bed 11 by the presence of a Dimorphoplites sp. of 
the chloris-bipiicatus group, and in another boring by Euhoplites opalinus. It is 
considerably attenuated in comparison with Beds V-VII at Folkestone. Bed 10 has 
yielded a crushed Dimorphoplites niobe which might indicate either the meandrinus, 
subdelaruei, or niobe Subzones. Neither Bed 9 nor the bulk of Bed 8 yielded any 
zonally significant ammonites but crushed Falciferella occurs in the lower 6 inches 
(1-828 m.) of Bed 8 which suggest the intermedins Subzone or possibly the niobe 
Subzone. Anahoplites of the intermedins group occur from 1 foot (0-304 m.) above 
the base of Bed 7, and in Bed 6, definitely indicating the presence of the intermedins 
Subzone. No subzonally diagnostic ammonites are known from Beds 5 and 4, but 
Bed 3 contains phosphatised fragments of H. (H.) persnlcatns and H. (H.) of the 
paronai group. This is the direct equivalent of Bed I (v) at Folkestone, the dentatns 
nodule bed, classified with the spathi Subzone. It is highly probable that Bed 4 
above is the equivalent of Bed I (vi) at Folkestone (p. 12). 

The particularly interesting feature of the sequence occurs in Bed 2. This bed is 
classified with the lyelli Subzone, and contains species of Protanisoceras (P.) at only 
12 and 15 inches (0-304-0-381 m.) below Bed 3, and species of Hopiites (H.) occur 
throughout. This sequence bears comparison with the lower part of the Gault in the 
Guilford, and Chislet Collieries where the lyelli Subzone is also well developed. At 
Folkestone, the lyelli Subzone is very condensed and is represented within Bed I (iv) . 
Whether the eodentatns Subzone is represented within the higher part of Bed 1 is 
uncertain in the absence of ammonites but it is highly likely when one considers the 
development of the lyelli Subzone here. The lower part of Bed 1 is probably equiv- 
alent to the ' Sulphur ' Band at Folkestone. 



IN THE ANGLO-PARIS BASIN 



79 



Bed 
No. 



par 



Uthology 



eriitalum Subzontt 



Mld-gr«y shelly clay with Inoceramut concentrlcus 



Light fawn shelly grey clay with dark burrows 



Shelly battleship grey clay with small brown phosphatic 
nodules In the basal linen 



Light fawn tough shelly clay with Falciferella 



Medium grey shelly clay with crushed Anahoplltes 
Intermedius 



Gritty grey burrowed shelly clay 



Mid grey shelly clay becoming paler below with 
scattered pale buff phosphatic clots 



Gritty burrowed grey clay sparsely shelly with 
glauconite in lower half 



Blockish phosphatic nodules in gritty gjauconitic grey cloy J <-■ 



Mid grey fine clay shelly and burrowed. In lowest 2ft 
Ifn clay becomes gritty. In lowest 4 ins glauconite 
and black phosphatic fragments occur 



Grey sllty clay with light burrows and phosphatic nodules 



If 



Ft ln« M 
(467 3) 



2 3 

4 

2 



10 1 2 



2 1 
633 4)0-! 



Fig. 32. Lower Gault sequence in the Dover No. 1 (Aycliff) boring, Kent (TR 294395). 



So MIDDLE ALBIAN STRATIGRAPHY 

These borings in the area of the Kent Coalfield show that the sequence in the Lower 
Gault expands considerably eastwards from the outcrop between Folkestone and 
Maidstone. In this trough area the eodentatus and lyelli Subzones are well developed. 
The whole sequence thins towards the coastal margin of Kent from the Isle of Thanet 
to St. Margaret's Bay northeast of Dover. 

F. Selection of sections in France 

It is not possible here to describe the Middle Albian stratigraphy of northern and 
central France in the same detail as the English sections. The French sections 
require just as long and careful study, and must include temporary sections seldom 
available on a chance visit and which are thus the prerogative of our colleagues in 
France. The purpose of this portion of the work is to make a comparison of the 
English sequence with a representative selection of sections of four regions ; (i) the 
Boulonnais ; (ii) the outcrop extending from the River Ornain (Meuse) to the River 
Armance (Yonne) which includes also parts of the Departements of Meuse, Marne, 
Haute-Marne, Aube and Yonne ; (iii) the Pays de Bray ; and (iv) the Pays de Caux 
(text-fig. 33). 

(i) COMPARISON BETWEEN WISSANT & FOLKESTONE 

The Albian deposits of the Boulonnais describe a narrow outcrop at the foot of the 
Chalk escarpment extending from the coast at Petit Blanc Ne'z south-eastwards to 
Lottinghen and then roughly westwards towards the coast to disappear beneath the 
dunes at Hardelot Plage. The deposits rest upon Aptian sediments at Wissant, but 
inland they may rest directly upon Aptian, ' Wealden ', Jurassic, and, near Caffiers, 
on Palaeozoic rocks. The exposures in the shore and in the cliffs between Wissant 
and Petit Blanc Nez are indicated in text-fig. 34. 

The Gault of the Wissant area was briefly described by Barrois (1873, 1875, 1878, 
but particularly 1879 ; 27-28), Price (1879, I 88o ; 34 etc.) and Jukes-Browne (1900 ; 
378-381), but it was not until 1938 (a 98-121) that a good detailed description was 
given by J. -P. & P. Destombes. Barrois had considered that the sequences at 
Folkestone and Wissant were not comparable in detail, a conclusion with which the 
present writer agrees. Destombes & Destombes, however, followed Price in consider- 
ing that the Wissant succession is comparable to that of Folkestone, although reduced 
in thickness ; a view accepted by Spath (1943 ; 721). 

P. & P. -J. Destombes have written an emended account of the Wissant sequence 
(1965 ; 257-260), the lithological accuracy of which can be confirmed by the writer's 
own examination of the section. However, their subzonal classification of 1938 and 
the implied classification of 1965 requires some revision at certain levels as also does 
the account by Marie (1965 ; 280-284, table 1). In April 1967 the writer observed 
good clean sections in the Lower Gault both in the cliffs and in the foreshore, and 
from the study of these the graphical section (text-fig. 35) has been drawn. The 
primary bed numbers employed are those used by Destombes & Destombes (1965 ; 
258), and the correlation with Folkestone is shown in text-fig. 36. 







PARIS 



OCHATEAUDUN 




CHATILLON sur SEINE 



Fig. 33. Sketch map of the outcrop of Albian sediments in the Paris Basin showing the positions of the sections mentioned in the text. 
The pecked line represents the approximate margin of Albian sediments buried beneath overlapping Upper Cretaceous sediments. 



IN THE ANGLO-PARIS BASIN 



81 



N 



CHANNEL 




1 mile 

J 



1 km 



Fig. 34. Sketch map of the coast between Wissant and Cap Blanc Nez, Pas de Calais 
(modified from J-P. & P Destombes 1963). 



MIDDLE ALBIAN STRATIGRAPHY 



At the point marked X on the sketch-map (text-fig. 34) a vertical section normally 
buried within the dune sands showed a sequence from the Argiles d'Ostrea Leymerii 
(Upper Aptian) up into the lower part of the Lower Gault 1 . Price (1879, Io> 8o ; 34) 



Bed 



1 3 



12 



10 
9 



L i t h ol og y 



Blackish phosphotic nodules, mainly cost 3 ot fossils \ 
preserved, in shelly grey clay. 



ith portions ot the shell 



(v) Burrowed grey clay, the burrows having pale infill inqs. 



(Iv) Very dark grey clay with a few scattered part-phosphatised fossils 
with the nacreous shell preserved. A line of scattered phosphatic 
nodules occurs 2 inches from the base. 



(lll)Part phosphatlsed fossils in extensively burrowed clay. 



(il)Grey burrowed shelly clay. 



(i)Dark grey shelly clay. 



Black angular phosphatic nodules in grey clay. 



Darkish grey clay with scattered shells, and with a scattered 
line of phosphatic nodules buff in colour. 



Grey shelly clay. 



(II) Sparsely shelly well-bedded dark grey clay. 



(i) Glauconitic blocky dark grey clay, wl.th a thin bedded Junction 
with 8(H) above, and becoming progressively more 
glauconitic downwards. 



Large brown grey phosphatic nodules with abraded upper surfaces, some compound, 
with smaller black phosphotic nodulesond fragments of fossils, m glauconitic loa 



1! 



j*~r_- .'.* 



fcuP^&SSfe 



Ft Ins M 

- 2-4 



5- 



3- 



2- 



6 
2 - 



Fig. 35. Section in Lower Gault in the sea-cliff extending from point X on the sketch map 
(Fig. 34) up to the old german block-house 0.4 km SW. of Strouanne, Wissant, Pas de 
Calais. 



had stated that at Wissant the ' Ammonites-mammillaris Zone and the A .-interruptus 
zone (Bed I) are mixed together, so much so that it is difficult to divide them ; but the 

fossils from the former have the greensand matrix '. Now, in Bed 7 in the section 

mentioned above, a magnificent fauna of puzosianus Subzone age was collected by 
the writer preserved in exactly the manner described by Price and associated with a 
spathi Subzone fauna. The large puzosianus Subzone nodules had obviously stood 

1 It appears to be the first time this century that this section has been seen. It was described by Gaudry 
(i860). Le Hon (1864 ; 14-16), and Barrois (1879). The section examined by Dutertre, in company 
with Kirkaldy (1938 ; 121-2), was situated in the cliffs near the farm of Saint P6. I can confirm the 
accuracy of Barrois' section from a point about 4 ft. (1-21 m.) below the top of the Argiles d'Ostrea 
Leymerii up to the top of the Sables Vert. 



IN THE ANGLO-PARIS BASIN 83 

up as a hard-ground on the spathi Subzone sea floor for their upper surfaces are 
strongly eroded (text-fig. 35) . The currents had scoured out the sandy matrix from 
around the nodules, and, subsequently, phosphatic fragments from a later spathi 
Subzone period of erosion accompanied by a gritty clay sediment were forced into the 
crevices between and even underneath the nodules of ptizosianus age. J. -P. & P. 
Destombes record ' Protohoplites raulinianus ' from this bed (1938a ; 102). 

In the foreshore to the NE. up to Strouanne, these puzosianus Subzone phosphatic 
nodules are still present but are scattered and much more rolled : they have not 
yielded fossils. In the reef on the foreshore in front of Petit Blanc Nez a few putty- 
coloured gritty well-rolled smaller phosphatic nodules of puzosianus Subzone type 
still occur mixed in with the predominantly spathi Subzone debris. It can be seen, 
therefore, that the degree of reworking increases north-eastwards from the cliff 
section near Wissant. In this respect it is important to note that the Palaeozoic 
floor rises sharply off-shore (J. -P. & P. Destombes 1963 ; 53 text-fig. 3). 

There is no evidence of the presence of an eodentatus or lyelli Subzone element in 
Bed 7, and the spathi element is strongly reminiscent of the fauna in Division A in 
the Maidstone By-Pass (p. 38) which indicates that the earliest part of the spathi 
Subzone may not be represented either. The equivalent of the Greensand Seam and 
the basal spathi Subzone element of the dentatus nodule bed at Folkestone is, there- 
fore, absent at Wissant. 

It is not easy to make out the complete sequence between Bed 7 and Bed 11 and it 
is possible that these clays might be somewhat thicker than has been previously 
recorded. Nonetheless, for the purpose of this account, the general sequence given 
by P. & J. -P. Destombes will be the one considered. Hopiites (H.) occurs crushed in 
the matrix of Bed 7 and in the lower 3 inches of Bed 8 (i), and these sediments are 
classified with the spathi Subzone. The base of the intermedius Subzone has not been 
satisfactorily defined but probably commences at the base of 8 (ii). Scattered 
crushed examples of Anahoplites intermedius & A. praecox occur throughout the bulk 
of 8 (ii) and P. Destombes records Falciferella in the uppermost 8 inches (20 cms) 
(1962 ; 196-7). Bed 8 (ii) is, therefore, classified with the intermedius Subzone, 
however, as can be seen from the section and the general nature of the fauna it differs 
greatly from the upper part of Bed I and Bed II at Folkestone. P. Destombes (1962) 
classifies the bed later numbered 9 with the niobe Subzone and this must also include 
Bed 10. 

Bed 11 has yielded a remanie fauna of ammonites including Mojsisovicsia sub- 
delaruei & M. remotum indicating the subdelaruei Subzone, Euhoplites of the mean- 
drinus group indicating that Subzone, and also fragments of Euhoplites lautus and 
E. nitidus indicating the nitidus Subzone. The degree of condensation at Wissant is, 
therefore, greater than that represented by Bed IV at Folkestone and includes mater- 
ial also found in the nitidus Subzone sediments of Bed V. 

The nitidus Subzone is well developed in Bed 12 (i-iv) and the preservation of the 
fossils particularly in 12 (iii) is identical to that of Bed V-VI at Folkestone. It is 
possible that 12 (iv) may represent the equivalent of the lower part of Bed VII below 
the base of the daviesi Subzone but there is no certain evidence for this. However, 
it is certain that there is an important break in the sequence between 12 (iv) and (v), 



8 4 



MIDDLE ALBIAN STRATIGRAPHY 



FOLKESTONE 




0-1-0 radmli m f » »«»# |[ii) 



Fig. 36. Correlation of Lower Gault sections at Folkestone and Wissant. 



IN THE ANGLO-PARIS BASIN 8 5 

and that the daviesi Subzone is absent at Wissant. At the base of Bed 12 (v) 
Inoceramus concentricus is present but as one works up through the bed it passes 
through a subsulcatus stage to achieve the form of i". sulcatus just below the cristatum 
nodule bed 13 (cf. P. & J. -P. Destombes 1965 ; 260). Beudanticeras beudanti also 
occurs partly crushed with its shell, and it should be borne in mind that d'Orbigny's 
holotype of Dipoloceras bouchardianum is from Wissant and is pyritic with the shell ; 
it almost certainly came from 12 (v). Anahoplites daviesi and its close relatives are 
absent and in fact the fauna is that which occurs in the lower nodule bed of Bed VIII 
at Folkestone minus the late daviesi Subzone element (p. 15) absent at Wissant. 
Therefore, the lower part of the cristatum Subzone is represented at Wissant by these 
clays of 12 (v) and this is the only proven section known to the writer where the basal 
part of the Upper Albian is represented by an uncondensed sequence. Bed 12 (v) 
certainly does not belong to the daviesi Subzone as Marie (1965 ; 279) has indicated. 

It is worth recording here that Bed 13 at Wissant contains a remanie ammonite 
fauna which indicates that it represents Bed VIII (ii & iii) at Folkestone together 
with the clays of Bed IX up to the level at which Hysteroceras orbignyi becomes 
common. The Euhoplites inornatus level, which provides a useful indicator horizon 
in the lower part of the Upper Albian, is caught up within Bed 13. This bed re- 
presents, therefore, the bulk of the cristatum Subzone together with what has been 
considered previously to be the lower part of the orbignyi Subzone (see also p. 126). 

The original account by Barrois (1875a) of the succession between the Wissant area 
of the Boulonnais and the Departement of the Meuse has had very little added to it. 
This area includes the Ardennes where Barrois demonstrated the major stratigraphic 
break which exists between the spathi Subzone and the sediments of Upper Albian age 
classified by him with his ' Zone of Ammonites inflatus ' which he included in the 
Cenomanian. The sequence in the dentatus Zone is itself incomplete, reflecting the 
proximity of the area to the Variscan massifs to the east. In the Departement of the 
Meuse, the Middle Albian sediments begin to thicken and it is at Revigny-sur-Ornain 
that the more detailed account of the sequence in the southern part of the Paris 
Basin commences. 

(ii) THE OUTCROP FROM THE RIVER ORNAIN (MEUSE) 
TO THE RIVER ARMANCE (YONNE) 

The outcrop of the Albian sediments in the southern part of the Paris Basin is 
shown in text-fig. 33. This strip of country is the classic area for the study of the 
French Albian ; the name Albian stems from the Roman province of Alba, now the 
Departement of the Aube. It includes the portions of the Departements of the 
Meuse, Marne, Haute Marne, Aube and Yonne, divided into the old regions of the 
Argonne (part), then Perthois, and part of the Puisaye. The succession and its 
facies changes at the outcrop can be demonstrated by brief descriptions of the follow- 
ing seven sections (a) Revigny-sur-Ornain (Meuse) ; (b) Pargny-sur-Saulx (Marne) ; 
(c) Les Cotes-Noires pres de Moeslain (Haute-Marne) ; (d) Courcelles pres Clerey 
(Aube) ; (e) La Vendue Mignot (Aube) ; (f) St. Florentin area (Yonne). 

These sections demonstrate the important development of the dentatus Zone and 



86 MIDDLE ALBIAN STRATIGRAPHY 

in particular of the eodentatus and lyelli Subzones in this area. The clay facies of the 
dentatus Zone passes rapidly in the St. Florentin area to a predominately sandy facies 
characteristic of the succession in the Puisaye-Yonne, Nievre, Cher, indicating the 
proximity of the Variscan massif of Morvan. In the whole area under consideration 
the proved sediments of loricatus Zone age represent only the intermedins Subzone 
and in the Puisaye these are largely remanie. Sediments of lautus Zone age have 
not yet been detected. 

This area has been studied by many French Cretaceous workers. One of the 
earliest papers written was by Michelin (1838) on the sequence at Gaty, pres Geraudot 
(Aube). Leymerie (1841, 1842) then described the Gault in the Aube but, unfortun- 
ately, d'Orbigny (1841) just antedated Leymerie's description of Ammonites lyelli 
one of the most characteristic fossils. This was followed by a similar description 
of the Gault in the Departement of the Meuse by Buvignier (1852). Various papers 
on individual localities were then published but the next important work before 
Barrois was that of Ebray (1863) who attempted to coordinate the sequence in the 
various Departements. 

Barrois made the first attempt to tie in the apparently different sequences of the 
Boulonnais, Ardennes, and the strip of country from the Meuse to the Nievre (1875). 
Unfortunately, two very inaccurate attempts were made to correlate the succession 
in the Aube with that of Folkestone (Price & Delatour in Price 1879 ; 1880 ; 37-40, 
Jukes-Browne 1900 ; 388-390). The result completely obliterated Barrois's work in 
English minds, and eventually led to a great deal of uncertainty as to the strati- 
graphical position of the clays containing Ammonites lyelli in relation to the sequence 
known in England. This uncertainty was not completely settled even by Spath 
(e.g. 1926b ; 1943, 722). It was not until Wright & Wright demonstrated the 
occurrence of Lyelliceras in the ' benettianus ' Subzone in Surrey (1948), and the 
stratigraphical position more definitely indicated by Casey (1961a) that the question 
was put beyond doubt in English minds. 

The first general account of the Albian in this area of France to appear after 
Barrois was a paper by Lemoine (1910). Larcher (1937) subsequently produced a 
very interesting paper in which the fauna of the broad lithological units were listed 
accurately for the first time. However, it was not until 1965 that a more detailed 
picture of the sequence and its facies changes could be obtained. Four very im- 
portant papers were presented to the Colloque sur le Cretace inferieur held in Lyon in 
1963. These were published in 1965 and written by : — Larcher, Rat, & Malapris ; 
P. & J.-P. Destombes ; Marie ; and Ciry, Rat, Malapris & Nicolas. Of these, the 
paper by P. & J.-P. Destombes is of paramount importance. Recently, Lauverjat 
(1969) has described the broad lithological sequence and facies changes shown by 
deep borings through the Chalk along two lines, parallel to the Albian sediment out- 
crop, from the area of Troyes (Aube) south west to the river Loing ( Yonne) . 

(a) Revigny-sur-Ornain (Meuse) 

Barrois demonstrated (1878), that in the northern part of the Argonne (part of the 
Departements of the Ardennes, Meuse, and Marne) sediments now included in the 



Div. 



IN THE ANGLO-PARIS BASIN 

Lithology 



87 



Ft Ins M. 



Rather fawn blocky marly clay somewhat ferruginous; 
shelly with numerous Inoceromus concentrtcus. The clay 
passes near the base into soft marlstone. 



(Ill) Blocky dark fawn grey shelly clay in lower part 
becoming more massive beddad upwards-the fossils 
losing the shell until near the top where shells ara 
preserved again. 



(II) Phosphatlc nodules and part-phosphatlsed and pyrltic fossils . 
In fawn grey sllty clay. _/ 



(I) Fawn grey slightly sllty shelly clay, weathering to a 
reddish colour, with scattered pyritlc ammonites. 




30 



Fig. 37. Section in Gault at the claypit of the Soci6t6 B.H.T.P. on the SE. side of the 
Marne-Rhine canal, about 2 km S. of the centre of Revigny-sur-Ornain, Meuse. 



88 MIDDLE ALBIAN STRATIGRAPHY 

Middle Albian appear and thicken southwards. Deposits of lyelli Subzone age, 
although no longer exposed, are present in this area. Buvignier (1852 ; 525-6 & 
pi. explanation p. 45) lists lyelli Subzone fossils from as far N. as Clermont-en- 
Argonne, 31 kms NNE. of Revigny-sur-Ornain. These include Pseudhelicoceras 
argonnenis (type locality), Brancoceras versicostatum and Lyelliceras lyelli (although 
he states on p. 521 that the only locality at which this species had been found was 
at Senard about 17 kms a little E. of N. of Revigny-sur-Ornain). From Revigny- 
sur-Ornain itself, and, in the case of the last-named species below, between here and 
Mussey (presumably from the excavation for the Marne-Rhine Canal) he records 
Nucula bivirgata, Protanisoceras (P.) alternotuberculahim, P. (P.) moreanum (type 
locality), P. (P.) nodoneum (type locality) and P. (P.) barrense (type locality). 

Approximately 2 kms S. of the centre of Revigny-sur-Ornain, and to the SE. of the 
N 395, the Societe B.H.T.P. have a large brick and tile works with an extensive 
clay pit on the SE. side of the Marne-Rhine canal. The pit is worked in two stages by 
multi-bucket excavators and a sketch section is given in text-fig. 37. Deposition of 
sediment here was apparently fairly constant and there is an almost perfect transition 
from the lithology seen at the base to that seen at the top. The only sign of slight 
condensation occurs approximately 30 feet (9-14 m.) above the base of the section 
where part-phosphatised and pyritic fossils are more common. 

The fossils are essentially crushed flat, and at the base of the sequence the ammon- 
ites consist of Hoplites (H.) spp. including H. (H.) dentatus and Metahamites sablieri 
(d'Orbigny) indicating the spathi Subzone. A higher spathi Subzone fauna ranges 
up into the top few feet of Division 1, and the band of phosphatised and pyritised 
fossils about 30 feet (9-14 m.) from the base has yielded ammonites including H. (H.) 
aff. dorsetensis Spath, H. (H.) pretethydis Spath, and H. (H.) canavariformis com- 
parable to those found in the upper part of the spathi Subzone in the Weald. 

Anahoplites praecox and A. intermedins appear at the base of Division 2 and range 
up through the remainder of the measured sequence. In Dr. P. Destombes' collection 
there is a single example of the sulcate form of A . praecox which indicates the lower 
part of the intermedins Subzone and was probably derived from the top few feet of 
Division 1. 

The spathi Subzone is represented in this section, therefore, by about 50 feet 
(15-24 m.) of sediments, and the base of the Subzone has not yet been reached. The 
top of the intermedins Subzone has not been reached either, and the exposed portion 
of sediments belonging to this Subzone is about 15 feet (4-57 m.) thick. 

(b) Pargny-sur-Saulx (Marne) 

In the area of Pargny-sur-Saulx and Maurupt, situated approximately 12 kms SW. 
of the section at Revigny-sur-Ornain, there is an important centre of brick and tile 
production. Houdard (1940 ; 625-636) has recorded the distribution of the fauna 
collected from the Gault (Argiles Tegulines) in this area but there are no details of the 
sections. From his lists it is apparent that the lyelli and spathi Subzones are definitely 
present, and probably the intermedins Subzones as at Revigny. His record of 
' Acanthoceras ' camatteanum and ' Parahoplites ' steinmanni from Pargny suggested 



IN THE ANGLO-PARIS BASIN 



89 



that the eodentatus Subzone might also be present. The section between Pargny-sur- 
Saulx and Maurupt described below provides new information on the basal part of 
the Middle Albian in this area. 

The extensive clay pit belonging to the brick and tile works of the Hugenot Freres, 
situated a few hundred yards E. of the D61, 1 kmNNW. of Maurupt, has been deepened 
and shows the lithological sequence given in text-fig. 38. Bed 1 did not yield 
ammonites to the writer but bivalves are common. It is possible, although by no 
means certain, that it is of uppermost mammillatum Zone age. Bed 2 has yielded 
phosphatised or pyritised Hopiites (Isohoplites) eodentatus, H. (I.) sp., Beudanticeras 
albense, B. sanctaecrucis, Otohopiites sp., Lyelliceras camatteanum (d'Orbigny), 
Brancoceras sp., indicating the eodentatus Subzone, and its top is an erosion surface. 
The sediments of Bed 3 contain crushed fossils including ammonites, some quite large, 
such as Hopiites (H.) spp., Lyelliceras of lyelli Subzone appearance, and Douvilleiceras 
sp., and can be classified with the basal part of the lyelli Subzone. 



Bed 



Li thology 



Ft Ins M 



Fawn-gray slightly silty clay, shelly, with i ron-staine d 
partings. Some fossils are partly phosphatised. 



(II) Black phosphatic nodules scattered in fawn grey silty clay. 



(i ) Fawn-grey shelly clay, silty with iron stained partings. 
Part-phosphatised and part-pyritic ammonites occur 
scattered throughout. 



V 



Silty fawn-grey shelly clay with some pyritic fossils 



3 6 



4 5 



Fig. 38. Section in basal Gault exposed in the claypit of the Hugenot Freres, situated a 
few hundred yards E. of the D 61 road, 1 km NNW. of Maurupt, and 1-4 km S. of Pargny- 
sur-Saulx, Marne. 



(c) Les C6tes Noires (Haute Marne) 

Approximately 15 kms SSE. of the section described above is the natural river cliff 
of Les Cotes Noires situated on the W. bank of the River Marne 1 km to the W. of 
Moeslain, near St. Dizier. This magnificent natural section can only be safely 
worked in reasonably dry weather and is approached by way of the summit of the 



9° 



MIDDLE ALBIAN STRATIGRAPHY 



LI thology 



Yellow gray cloy- 



More calcareous clay with pyrito phosphatlc ammonites. 



Blue black micaceous clay with gypsum crystals and 
scattered phosphatlc nodules. 



Grey micaceous clay. 



Black micaceous clay. 



Ft Ins M 



Fig. 39. Section in Middle Albian sediments (largely after P. 8c J-P. Destombes 1965) 
at Les Cotes Noires, 1 km W. of Moeslain on W. bank of the river Marne (Haute Marne). 



IN THE ANGLO-PARIS BASIN 91 

cliff from the D196 between St. Aubin and Laneuville-au-Pont. The section has 
recently been described by P. & J. -P. Destombes and is quoted in text-fig. 39. It 
forms one of the original localities cited by d'Orbigny when defining the stage (1842 ; 
404) and is doubly important because it shows a complete sequence from the mam- 
millatum Zone to the spathi Subzone of the dentatus Zone. 

The outline classification of the sequence is as follows. The eodentatus Subzone is 
definitely represented within Bed 5 and may include 6 and the basal part of 7. The 
remainder of Bed 7 together with 8 contains a lyelli Subzone fauna, Bed 8 lithologic- 
ally represents the NE. extension of a marker horizon recognisable at the top of the 
lyelli Subzone in the Gault of the Aube and in the St. Florentin area of the Yonne 
(text-fig. 43). Bed 9 contains a spathi Subzone fauna. 

(d) Courcelles pres Clerey (Aube) 

This clay pit, No. 3 of the Tuileries de St. Parres les Vaudes, is situated to the E. of 
the river Seine on the eastern side of the D 49 about 2-5 kms SE. of Clerey. It now 
forms the most important section available in the Middle Albian sediments in the 
Aube, and is typical of the sequence formerly exposed at such famous localities as 
Dienville on the River Aube, and Gaty-pres Geraudot in the Foret d'Orient (Larcher, 
Rat & Malapris 1965 ; 246). It is very close to the old section at Courcelles figured 
by Leymerie (1846 ; pi. 3, fig. 4). The section is given in text-fig. 40, and its correla- 
tion with sections to the NE. and SW. in text-fig. 43. It has been described briefly 
by P. & J. -P. Destombes (1965 ; 262), and is particularly important in that it permits a 
direct comparison to be made with the sequence in the Horton Clay pit, Small Dole, 
Sussex (p. 35). 

Bed 1 to a metre above the base of Bed 4, are classified with the lyelli Subzone, and 
the following list of ammonites is certainly not exhaustive and represents material 
collected strictly in situ. Bed 1 is not very fossiliferous but has yielded Hoplites (H.) 
bullatus, H. (H.) dentatus group, Beudanticeras albense, Lyelliceras pseudolyelli 
(Parona & Bonarelli), L. aff . gevreyi. Bed 2 (i) Beudanticeras santaecrucis, Brancoceras 
sp., and on a bedding plane 1 foot (0-3 m.) from the base, Desmoceras latidorsatum is 
not uncommon and this horizon has also yielded a single example of Hypophylloceras. 
Bed 2 (ii) Brancoceras sp., Pseudhelicoceras argonnense. Bed 2 (iii) Lyelliceras lyelli, 
Brancoceras sp., Eubrancoceras aegoceratoides (Steinmann), ' Oxytropidoceras ' evansi. 
Bed 2 (iv) Desmoceras latidorsatum, Beudanticeras laevigatum, B. sanctaecrucis , B. 
albense, Hoplites (H.) sp. dentatus group, Lyelliceras gevreyi, Brancoceras spp., 
Protanisoceras (P.) alternotuberculatum, P. (P.) barrense P. (P.) nodoneum. Bed 2 (v) 
Beudanticeras laevigatum, Hoplites (H.) baylei, H. (H.) sp. dentatus group, P. (P.) 
alternotuberculatum, Pseudhelicoceras argonnense. Bed 3 Douvilleiceras clementinum, 
Hoplites (H.) dentatus, H. (H.) baylei, H. (H.) spp. Bed 4 basal 1 metre is character- 
ised by Hoplites (H.) spp. but P. & J.-P. Destombes record Douvilleiceras up to this 
height, and it is here included in the lyelli Subzone. 

In comparison with the Horton Clay pit, Small Dole, the fauna listed above shows 
the following important features. Bed 1 must be close to the underlying eodentatus 
Subzone for Lyelliceras pseudolyelli is directly transitional from Lyelliceras camatteanum 



92 



MIDDLE ALBIAN STRATIGRAPHY 



Ll t h o I o g y 



Weathered grey silty clay somewhat marly near the base 



Blackish phosphatic nodules .n weathered grey silty clay. 



Dark grey slightly silty clay with crushed shells and part pyntiscd 
fossils. Brownish phosphatic nodules are scattered throughout At 8 
feet from the base there is a seam of 'solid' pyritic ammonites. 
Approximately 2 inches above the base there is a similar bedding 
plane with well preserved fossils. 



Marly silty light grey clay with large concretions of silty shelly marl stone. 



(v) Darkish fawn- grey silty clay, shell y with scattered 'solid 1 pyri t ic 
fossils 



(iv) Mottled fawn-grey clay, silty with more numerous 'solid' pyritic ammonites, 



(III) Darkish fawn-grey shelly silty clay with scattered pyritic fossils. A 

distinct line of brown cavernous phosphatic nodules occurs 4 inches above 
the base, below which the clays become much siltler. 

(il) Mottled fawn-grey shelly clay sil t y with 'solldMossIl s. 



0) Darkish silty fawn-grey shelly clay with a bedding plane of scattered 
pyritic fossils at the middle. 



Dark grey silty clay with scattered line of phosphatic nodules 9 inches fron 
the top. 



Ft ins M. 



5^l" '." "_ <& 



Fig. 40. Gault section at the No. 3 claypit of the Tuileries de St. Parres les Vaudes at 
Courcelles pres Clerey on E. side of the river Seine, and to the E. of the D 49 road 2 - 5 km 
SE. of Clerey, Aube. 



IN THE ANGLO-PARIS BASIN 93 

of the eodentatus Subzone to Lyelliceras lyelli of the typical development of the lyelli 
Subzone. Beds 2 and 3 contain a closely comparable fauna to that of the English 
lyelli Subzone except that in England the Tethyan element represented by Desmoceras 
and Hypophylloceras is absent. Douvilleiceras clementinum is common in Bed 3 at 
Courcelles but this genus is very uncommon in the lyelli Subzone in England. The 
species of Brancoceras are somewhat different to those found in England and they 
frequently show a tendency to a zig-zag arrangement of the ribs as they sweep across 
the venter. The occurrence of Eubrancoceras aegoceratoides in Bed 2 (iii) is very 
important for long-range correlation (p. 135). 

The beautifully preserved fauna of Bed 3 includes also bivalves, gastropods, and 
corals, and it is this horizon that has yielded many of the fine specimens of Hoplites 
(H.) spp., and Douvilleiceras clementinum from such localities as Dienville, Gaty, or 
just Aube, found in museum collections. 

The remainder of Bed 4 contains a typical spathi Subzone fauna consisting essenti- 
ally of species of Hoplites (H.) together with Metahamites sablieri and Inoceramus 
concentricus. At a height of 8 feet (2-438 m.) from the base of Bed 4 there is a small 
thickness of clay with scattered pyritised ammonites and this has yielded to the 
author a single example of Mojsisovicsia delaruei compressa (Spath) . 

Bed 5 probably represents much of the higher part of the spathi Subzone sediments 
seen at Revigny-sur-Ornain (text-fig. 37), for the species of Hoplites at the top of Bed 
4 are not particularly high forms. Bed 6 above contains Anahoplites sp. indicating 
the extreme base of the intermedins Subzone. 

Larcher, Rat & Malapris (1965 ; 246) considered that the section at Villemoyenne 
(No. 1 of the Tuileries of St. Parres-les-Vaudes) showed a mammillatum Zone sequence. 
However, P. & J. -P. Destombes (1965 ; 263) and Marie (1965 ; table 1) indicated that 
there was overlap between the sequence exposed at Villemoyenne and that of 
Courcelles. The pit is extensive and the dip appears to be negligible. It is situated 
less than 2 kms SE. of the section at Courcelles and 0-5 km along the road from 
Villemoyenne to Le Ht. Villeneuve. An examination of the sequence has convinced 
the writer that it is wholly of high mammillatum Zone age, a conclusion which Dr. 
P. Destombes has also arrived at (personal communication). 

(e) La Vendue Mignot (Aube) 

The Tuilerie Le Clerc, situated about 200 yds W. of the Di and a few hundred 
yards S. of the D108 roads at La Vendue Mignot, has been nominated as the type 
section of the Subzone of Lyelliceras lyelli & Hoplites benettianus by P. & J. -P. 
Destombes (1965 ; 262, 266). The section is very shallow, like many of the smaller 
terriers in this region of France, but with the combination of a northerly 3 dip and 
the slope of the ground surface, approximately 16 feet of weathered clays are exposed 
(text -fig. 41). The section is situated about 9 kms WSW. of that of Courcelles pres 
Clerey, and the sequence although well weathered in its upper part is apparently the 
same. 

Bed 1 was seen to a depth of 7 feet (2-133 m.) but yielded no ammonites to the writer. 
At 2 inches (0-050 m.) above the base of 2 (i) a single example of Desmoceras latidor- 



"I 



MIDDLE ALBIAN STRATIGRAPHY 



satiiiu (Michelin) was found in sitn enabling a direct correlation to be made with 
Courcelles. Bed 2 (ii) at La Vendue Mignot corresponds to 2 (ii) at Courcelles, but 
yields a somewhat higher percentage of part-phosphatised fossils. The remainder of 
Bed 2 is too deeply weathered to permit the recognition of the remaining subdivisions 
seen at Courcelles, although its fauna grosso modo is the same as that listed above. In 
the soil at about the middle of the northern face of the pit, there are pieces of well 
weathered sandy marlstone yielding the fauna of Bed 3 at Courcelles. 

Although this is the nominated type section of the lyelli Subzone proposed by P. & 
J.-P. Destombes it shows neither the relationship with the eodentatus Subzone below 
or the spathi Subzone above. Neither does it show a complete sequence in the lyelli 
Subzone itself. 



Bed 



Li t hology 



Ft Ins M. 



Fragments of gritty marlstone in subsoil. 



Very weathed bullish sllty clay with some limonitic fossils 
in the lower part. 



(ii) Slightly lighter clay with part-phosphatised part-limonitic fossils. 



(i) Weathered buffish sllty clay with a few limonitic fossils. 



Weathered gritty glauconltic buffish clay. 




Fig. 41. Section in Gault at the Tuilerie Le Clerc, c. 200 yds W. of the D 1 road and a few- 
hundred yards S. of the D 108 road, at La Vendue Mignot, on the N. side of the Foret 
d'Aumont, Aube. 



(f) St. Florentin area (Yonne) 

The early work of Ebray (1863) and Hebert (1863) did not present a true picture 
of the Albian succession in the area of St. Florentin, and Lambert (1894, 1913) was 
the first worker to give a more correct sequence. Lambert's sequence was the one 



IN THE ANGLO-PARIS BASIN 



95 



quoted subsequently by Lemoine (1910). Houdard (1933) confirmed Lambert's 
observations and presented accurate and important new information. More recently 
P. & J. -P. Destombes (1965 ; 264-265) have reinterpreted the sequence indicating a 
facies change certainly within the spathi Subzone between St. Florentin and Montlehu 
a distance of barely 1 km. In this area the clay facies of the Perthois (the strip of 
country flanking the Chalk and including portions of the Departements of the Haute 
Marne, Aube, and Yonne) gives place to the predominantly sandy facies of the 
Puisaye (the similar strip of country stretching from the River Armance to the Loire) . 
No sediments of eodentatus Subzone age have been proved in this area. Although 
known to occur, lyelli Subzone sediments are no longer exposed, but from sections 
which existed formerly at St. Florentin, and to the SW. near Mont St. Sulpice, 
Seignalay and Beaumont, it is readily apparent from the old collections that the 
equivalent of Bed 3 at Courcelles is present. The fauna is the same but it is pre- 
served in a much grittier and pebbly matrix. Two sections in sediments of spathi 
Subzone age exist in this area today. 

Montlehu 

The Tuilerie Montlehu is situated immediately S. of the N77 at the village of that 
name. It exposes about 18 feet (5-48 m.) of weathered grey clays with crushed 
Hoplites (H.) spp., and Inoceramus concentricus , and is classified without doubt with 
the spathi Subzone. 

As one proceeds SW. the topography changes quickly, and St. Florentin is built 
upon the high ground formed by the essentially sandy deposits of both Middle and 
lower-Upper Albian age. 

Sabliere Binot 

This disused sandpit in the Sables de Frecambault at the SE. end of the town of 
St. Florentin is situated on the same quarried escarpment as that described by 
Houdard (1933 ; 47) . The pit, which is now being filled in, shows sediments of Middle 
& Upper Albian age (text-fig. 42). It has been mentioned by P. & J. -P. Destombes 
(1965 ; 264), and Marie (1965 ; table opp. p. 286) who includes additional information 
on the other sections in the area. 

Bed 1 has not yielded fossils but it lies above the equivalent of Bed 3 at Courcelles 
(lyelli Subzone), known to be present in this area. It is almost certainly of spathi 
Subzone age and is considered to be the equivalent of the clays exposed at Montlehu. 
Bed 2 shows the incoming of clay sediment and it seems to the writer that this part 
of the sequence is more likely to have been deposited at the same time as the clays at 
Montlehu. However, the only fossils found are phosphatised bivalves. Dr. P. 
Destombes has informed me that large Hoplites (H.) were obtained from Bed 3 during 
the quarrying operation. 

Bed 4, the Bed VII Graviers a Opis glareosa of Lambert, is of considerable interest. 
It can be divided into two very irregular subdivisions. A lower dark grey sub- 
division with Hoplites (H.) spp., derived from the spathi Subzone, and an upper 



9 6 



MIDDLE ALBIAN STRATIGRAPHY 



Ft ins M. 



Soft malm with buff phosphates and pyntlc concretions. 



B'ocky sandy yellowish molr 



Alternating broad seoms of gritty clay and sandy beds Incompletely 
seen. 



jrey gritty clay seen clear for I £ 

;oarse pebbly sandy loam with admixed grey clay. Phosphatlc nodul es occurN, 1 > 
n ro ughly two concentrations (see text). ** - 



In ro ughl y two 

Coarse hard phosphatised pebbly stone-band, dark-grey In top 4 inches with 

phosphatlc nodules. 



Coarse pebbly loamy sand with streaks of grey clay. 



(v) Coarse yollowlsh pebbly sand. 



(iv) Lentlclos of sandstone. 



(Ml) Coarse yellow pebbly sand. 



(II) Lentlcles of sandstone. 



(I) Coarse yellow pebbly sand. 



u^_L^- 3J 



:m- 



ET 



Fig. 42. Section in the Sables cle Frecambault at the Carriere Binot, on the escarpment 
at the SW. end of St. Florentin, a few hundred yards N. of the lane leading to Cr6cy, 
Yonne. 



IN THE ANGLO-PARIS BASIN 97 

lighter coloured subdivision which contains some material scoured out from the 
spathi Subzone sediments, and a predominant element derived from sediments of 
intermedins Subzone age. Indigenous Anahoplites intermedins and Inoceramns 
concentricus occur in the upper subdivision indicating that it is undoubtedly of 
intermedins Subzone age. The derived intermedins Subzone material includes 
species of Anahoplites which occur at the extreme top of the spathi Subzone and basal 
part of the intermedins Subzone in England. 

Bed 5 is still pebbly in its lower 1 foot (0-30 m.) but it has not yielded fossils to the 
writer. Marie indicates that at about the middle of Bed 5 at the base of an argil- 
laceous member the Upper Albian commences. 

(g) Summary 

The sections described briefly above provide a picture, albeit very imperfect, of 
Middle Albian sedimentation across the basin of deposition extending from the 
Kimmerian modified Palaeozoic massifs of the Ardennes on the NE. side to those of 
Morvan to the SW. (text-fig. 43). 

The only information available about the sediments of eodentatus Subzone age come 
from the sections near Maurupt and Les Cotes Noires, in the NE. It is a curious fact 
that as yet it has not been detected in the Aube or Yonne. This must be due to a 
lack of exposures for the sequence in the mammillatum Zone in the area of the Bois 
de Perchois (Aube) is very thick and the Middle Albian sediments here are also 
apparently of considerable thickness. In England deposits of eodentatus Subzone 
age are in general very condensed and ammonites are not common except at a very 
few localities. Species of Hopiites (Isohoplites) form the majority of the ammonite 
fauna, and its usual associate in France Lyelliceras of the camatteanum group, is 
exceedingly rare in England. 

Deposits of lyelli Subzones age already proven at Clermont-en-Argonne are also 
apparently thicker at Les Cotes Noires than in the Aube, but the lithological sequence 
is comparable from Les Cotes Noires to the St. Florentin area (Yonne). 

At Revigny-sur-Ornain it is obvious that the spathi Subzone is represented by 
thick sediments especially the upper part. Unfortunately, the top of the Subzone 
has not been exposed at Les Cotes Noires, but at Courcelles the upper part of the 
Subzone is represented by a single nodule bed. No information is available about the 
sequence until the St. Florentin area is reached where, between Montlehu and St. 
Florentin itself, there is a change from the argillaceous f acies of the Aube to the sandy 
facies of the Puisaye. 

The intermedins Subzone is now known from five localities. It is quite thick at 
Revigny-sur-Ornain and the top of the Subzone was not determined in the sequence. 
Intermedins Subzone ammonites were determined by Breistroffer at Montierender 
(Haute Marne) and Le Plessis (Aube) (P. & J.-P. Destombes 1965 ; 262). Only the 
basal part of the Subzone has as yet been determined at Courcelles. At St. Florentin 
and at other localities in the Puisaye, the Subzone is represented within condensed 
deposits. No other Middle Albian Subzones are as yet known in this area. 

Very little information is available about the stratigraphy of the Gault between 



9 8 



MIDDLE ALBIAN STRATIGRAPHY 



STFLORENTIN MONTUEHU 



M. Ft 



LA VENDUE 
MIGNOT 



COURCELLES LESC6TES 

NO I RES 



W?? 



33 



H3I 



REVIGNY 

ORNAIN 



INTERMEDIUM 



SPAtHI 
( lower) 



zxcsm. 3 



- subronal corr oiat Ion Una* 
■ llthologlcal correlation ^t^o^ 




% 

9 
9 

8 

7 

6 \ 

S 



Fig. 43. Correlation of Middle Albian sections from the Meuse to the Yonne. 



IN THE ANGLO-PARIS BASIN 99 

this area and the Pays de Bray. However, a comparison between the succession 
shown by the La Chapelle boring at St. Denis, Paris (Jukes-Browne 1900 ; 397) and 
that of St. Florentin (Yonne) and Villers St. Barthelemy in the Pays de Bray below 
shows that the predominantly sandy beds in the Yonne, fringing the massif of Morvan, 
give way to clays under Paris, but the sequence is thinner. The sequence thickens 
again northwards from Paris, and in the Paysde Bray the Middle Albian is represented 
by clays, and the Upper Albian by an Upper Greensand facies. The clay facies 
extends down to include at least the top of the mammillatum Zone towards the NW. 
end of the Bray. 

(iii) PAYS DE BRAY 

The Pays de Bray both geologically and scenically resembles the Weald (text-fig. 
33). The NE. side of the Bray dips very steeply beneath the Chalk and there is no 
information on the sequence on this side. However, at the NW. end and along the 
whole of the south western side the dip is much more gentle and brick-pits in the 
Gault have been opened at a number of places. Usable information has been ob- 
tained from only four of these : Briqueterie Ledoict, St. Martin, at the NW. end of the 
Bray (P. Destombes 1970 and in Pomerol & Feugueur 1968) ; a section near Forges- 
les-Eaux (P. Destombes 1958) ; and two sections in the area of Villers St. Barthelemy 
(J. -P. & P. Destombes 1938b). The position of these sections is indicated on 
text-fig. 33. 

The most detailed information on the Middle Albian sequence in this region yet 
published is contained in the two papers already cited by J. -P. & P. Destombes 
(1938b) and P. Destombes (1958). They demonstrate the presence of the eodentatus, 
lyelli, spathi and intermedins Subzones all in a clay facies. The niobe Subzone is 
indicated as being represented by sandy deposits (P. Destombes 1958) but no definite 
evidence has been published to support this. This is followed by a break in the 
sequence involving the remainder of the Middle Albian. 

(a) Villers St. Barthelemy 

Two sections were described by J. -P., & P. Destombes in this area (1938b ; 122, 
123) . Their section 1 is no longer exposed but showed deposits of both the spathi and 
intermedins Subzones which together are over 30 feet thick (9-15 m.). Section 2 is 
now well exposed and shows the sequence given in text-fig. 44. 

Bed 1 (ii) contains Otohoplites spp. including 0. destombesi, Beudanticeras spp. and 
Douvilleiceras spp., indicating the uppermost part of the mammillatum Zone. No 
fossils were seen in the lower part of 1 (iii) and it is not possible to say whether it is of 
eodentatus or basal lyelli age: the top of 1 (iii), however, contains crushed Hoplites 
(H.) spp. Bed 2 contains a good bivalve fauna but only a few crushed specimens of 
Beudanticeras cf. laevigatum, Protanisoceras (P.) sp. cf. barrense, and in Dr. P. 
Destombes' collection, a few examples of Lyelliceras lyelli. This bed definitely can 
be classified with the lyelli Subzone, as also can Bed 3 on the occurrence of a few 
crushed Beudanticeras at about the middle of the sequence. The basal part of Bed 4 



ioo MIDDLE ALBIAN STRATIGRAPHY 

however, contains large crushed Hoplites (H.) including H. (H.) cf . dentatus and H. (H. 
cf. maritimus sp. nov. indicating the lower part of the spathi Subzone. How much 
of this sequence overlaps that of section i, if at all, cannot be determined. Un- 
fortunately, during 1967 this section was rapidly expanded, and the higher part of 
the sequence seen in a rise has now been quarried away. 



Bed 



Lithology 



Weathersd grey sllty clay with large partly phosphat ised 
ammonites. Shells are replaced by pyrite. 



Dark grey somewhat sllty glauconitic clay with occasional 
phosphatic nodules. 



Fawnish grey clay burrowed by dark grey clay with a few 
crushed fossils with pyrite replaced shells. 



(III) Sandy glauconitic green grey clay with sandy pockets 
particularly In the lower part. 



(II) Hard ferruginous pan with white buff phosphatic nodules. 



(I ) Tough grey brown gritty loam. 






. ipuzos. 



Ft 



1 . ■ 1 1 rw 



Ins M 



4- 



3- 



2- 



1- 



1 

2 0- 1 



Fig. 44. Section in Gault in a claypit 08 km N. of the village of Villers St. Barthelemy, 
c. 150 yds E. of the D2 road, Pays de Bray. 



(b) Forges -Les-Eaux, & St. Martin 

Further north in the Pays de Bray, the eodentatus and lyelli Subzones sediments 
expand considerably and consist of shelly clays. The section in the Briqueterie 
Ledoict near St. Martin l'Hortien situated at the NW. end of the Pays de Bray has 
been described by P. Destombes, who introduced the writer to it. It shows a good 
development of clays of eodentatus Subzone age overlying high mammillatum zone 
clays (see P. Destombes 1970 & in Pomerol & Feugueur 1968 ; 129-130, where the 
locality is given as Bully). 

The lyelli Subzone is known from a section west of Forges-Les-Eaux where Fortin 
collected phosphatic and pyritic Lyelliceras with the shell, now in the Museum 
d'Histoire Naturelle, Rouen, which were recorded by P. Destombes (1958 ; 309). 



IN THE ANGLO-PARIS BASIN 101 

However, no detailed information on the sedimentary sequence in this Subzone in 
the northern area of the Bray has as yet been recorded. 

(iv) COMPARISON BETWEEN THE PAYS DE CAUX AND 
THE ISLE OF WIGHT 

The expansion of the sequence towards the NW. end of the Pays de Bray apparently 
increases further to the NW., for the deep boring at Puys, near Dieppe, showed a very 
considerable thickness of clay (Jukes-Browne 1900 ; 398). However, an unknown 
thickness of this clay must be of Upper Albian age, representing a facies change from 
the Upper Greensand sequence seen in the Pays de Bray. Jukes-Browne is probably 
wrong (1900 ; 398) in classifying only the lowest 67 feet (2 m.) of sandy black clay of 
the core with the Lower Gault, but in the absence of palaeontological evidence, the 
boring cannot be interpreted. In the Pays de Caux a somewhat different facies is 
seen reflecting the proximity of a marginal area of Middle Albian deposition. 

The Albian sediments of the Pays de Caux (Seine Maritime) are well exposed in the 
cliffs between St. Jouin and Le Havre. The Upper Albian Gaize rises from sea-level 
at the base of the Chalk cliffs to the N. of St. Jouin followed quickly by the Gault, 
and the top of the underlying Poudingue ferrugineux. Below these pebbly beds are 
sands of Upper Aptian age. In the area between Octeville and St. Adresse these 
sands are seen to rest upon Kimeridgian sediments, and in this area the whole 
sequence of Lower Cretaceous sediments can be seen sandwiched between the Chalk 
and the Kimmeridge Clay. However, along the entire coast from St. Jouin to Cap 
de la Heve a large number of rock falls tend to obscure the lower part of the Albian 
sequence in particular, nonetheless, it is possible to make out the succession at many 
points. 

Lennier (1867) first described the succession and provided the foundation upon 
which subsequent stratigraphic work has been based. His is still the only published 
section of the sequence at Cauville (1867 ; plate 4). The early history of research was 
summarised by Jukes-Browne & Hill (1896) who made the first major attempt to 
correlate Upper Albian and Cenomanian sediments in the Pays de Caux with those of 
southern England. Hill also provided some information on earlier Albian sediments 
and gave the first detailed accounts of the Albian sequence seen between Octeville 
and Ste. Adresse. Jukes-Browne (1900 ; 395-401) reviewed the Albian sediments in 
this area, presenting a useful picture but without any real detail. Subsequent 
stratigraphic work has tended to concentrate on the sequence at Cap de la Heve, as 
for example the recent important studies by P. Destombes (1958), Cayeux (i960), 
and Rioult (1962). Destombes (1958 ; 306-308) sets out to describe the Albian 
sediments between Le Havre and St. Jouin but, and this is important, he bases his 
account of the stratigraphy on the sequence seen at Cap de la Heve and Octeville. 
His classification of these sediments gives a good picture of the zonal sequence in this 
area. Cayeux (i960 ; 21-25) quotes large extracts from Destombes' paper, but adds 
to this important new information pointing out that the sequence in the Poudingue 
at Cauville shows marked lithological variation to those seen elsewhere. The 
account by Rioult (1962 ; 39-42) of the section at Cap de la Heve is very useful and he 



102 MIDDLE ALBIAN STRATIGRAPHY 

also presents a comparison with the Albian sequence in the Isle of Wight and the 
Dorset and Devon coastal area. All three papers ably summarise the earlier 
literature. 

As Cayeux (1962 ; 2) has pointed out, the stratigraphy of the Albian sediments 
between Cap de la Heve and St. Jouin needs revision. Such a revision requires 
patient study because of the rarity of age diagnostic fossils. The following account 
is quite obviously incomplete but it adds some new information on the succession and 
provides a much more accurate foundation for the correlation of the sediments seen 
in the Pays de Caux with those of the Isle of Wight. In this section of the work the 
full exposed sequence of the Aptian and Albian sediments up to the base of the Gaize 
is recorded. The terms ' Poudingue ferrugineux ', & ' Argiles du Gault ' of Lennier 
(1867) cannot be accurately delimited in all the sections. 

It is essential that these sections are worked with the greatest care particularly in 
the early spring months. Winter frosts and the general freezing of ground water 
cause the shattering of the Chalk in the cliffs and large blocks can be dislodged merely 
by the ringing note of a hammer or by the slight vibration of a heavy surf. Major 
cliff falls are not infrequent during the early months of the year, but the collecting is 
far better at these times ! 

The sections described below indicate that the cliffs between St. Jouin and Cap de 
la Heve present a cross section through a depositional trough. The Lower Albian 
sediments are slightly comparable to those of the Isle of Wight, but those of the 
Middle Albian are quite different. 

(a) St. Jouin 

The section described in text-fig. 45 is exposed about 300 yds S. of the cliff-top car 
park west of St. Jouin. It has not previously been described, and includes Lower, 
Middle and Upper Albian sediments up to the base of the Gaize. Unfortunately no 
age diagnostic Middle Albian fossils have been found here by the writer and the 
correlation of this section with that of Cauville (text-fig. 49) is based purely on the 
lithology, and is, therefore, suspect in detail. 

(b) Cauville 

From approximately 50 yds SW. of the waterfall to about 300 yds NE. of it there 
are good sections interrupted by cliff falls (text -fig. 46). As Cayeux has indicated 
(i960 ; 23), there are striking variations in the Poudingue, the sediments of the 
mammillatum and Ptardefurcata Zones, in this area. This is well shown in the four 
sections described here for the first time, however, the Middle and Upper Albian 
sediments remain reasonably constant. 

Beds 1-9 are of Lower Albian, essentially mammillatum Zone, age. In the Bucaille 
collection in the Museum d'Histoire Naturelle, Rouen, there are three specimens of 
Hoplites (Isohoplites) and one specimen of Hoplites (H.) which come from Cauville. 
They are preserved in blackish phosphate with traces of the inner nacreous layer of 
the shell preserved, and with evidence of pyritic inner whorls and glauconitic loamy 



IN THE ANGLO-PARIS BASIN 



i°3 



Bed 



16 First concretionary stone band of the Goize. 



15 



13 



10 



L i t h o I og y 



Tough blocky grey sandy malm with scattered pale phosph- 
atic nodules. 



Argillaceous dark grey silty glauconitic sediment resting 
on the guttered upper surface of Bed 13 below, becoming 
more of a clay upwards, then pasting into about 6 inches 
of hard shaley grey shelly clay. 



Highly glauconitic blackish loam resting on a guttered 
surface of Bed 12 below. Pyritic concretions occur 
throughout. 



Highly glauconitic very dark grey loam a bit pebby 
passing down by rafts into sparsely shelly loam resting 
on guttered surface of Bed 11 below. 



Tough fawn sandy clay with brown phosphatic nodules 
with dark interiors, septorian at the top. 



Very pebbly grey loam with crushed bivalves. 



Dark grey less pebbly clay than Bed 8 with intercalations of 
dirty yellowish sand. Scattered nacreous shel Is. occur. 



Pebbly dark grey ill-graded fossilif erous sandy clay with 
nacreous shells preserved. 



Hard gritty concretions in tough grey pebbly clayey matrix. 



Tough ill graded ferruginous loam with phosphates ft. gri t. 



Ferruginous pebbly sand with some streaks of grey clay. 
Lenticles of grit occur near the top. 



Scattered sandy phosphatic nodules in brown pebbly sandy loar 



Rather pebbly streaked grey loamy clay and brown sand. 



Mottled grey sandy clay-loam, and brown sand less pebbly 
than Bed 1 into which it passes. 



Pebbly dark grey green loam with streaks of brown sand 
becoming fewer downwards. In the top of the bed there 
occur pebbly concretionary sandstone lenticles 4-5inches thick. 



F=Er~m=l 



Ft Ins M 



<iiii£r 



3 

to 

A 



11- 



10- 



9- 



8- 



7- 



3 6- 



5- 



1 





1 


6 


1 


4 
2 


1 


5 




8 
4-6 3 



2- 



0-J 



Fig. 45. Sequence in the Poudingue and Gault in the sea-cliff, c. 150 yds SW. of the cliff 
path exit, St. Jouin Bruneval, Pays de Caux. 



Llthology 
Hard light-grey concretionary sandstone. Basal bed of the Gaize. 



Light-grey cross-bedded sandy marly cloy wi 



th a few concretions. 



Grey glauconitic clay-loam with black, buff-ri n ded, phosphatic nodules at top and bottom 



(v) Dark grey glauconitic slightly pebbly loam. 



Civ) Thin seam of irregular blockish light-rinded phosphatic nodules in loam. 



(iii) Lighter grey glauconitic sparsely shelly loam. 



(ii) Thin seam of scattered blackish light-rinded phosphatic nodules in loam. 



(i) Darkish grey glauconitic shelly loar 



Very shelly gritty glauconitic fawny pebbly loamy clay with rolled fragments of fawn clay in the basal fe\ 
inches, pebbly patches at the top, and a few concretions. 



■ /f\ Uj 
o 
V Z ■ 

-was 



11 

10 

9 



Streaked dark green glauconitic sandy pebbly loam, with a few phosphatic nodules. 
Black clay channelled into the bed below. 



Irregular bed of pebbly ferruginous sand with large quortzite pebbles and phosphatic nodules. 



Grey greenish glauconitic loam with a 4 inch thick oxydised zone at the top. In the two and sections there 
is a single bed of grey pebbly sandy concretions, very hard, with phosphatic nodules in the lower part. 
Between the two end sections, on upper bed of less pebbly grey green sandstone lenticles appears in the 
sequence. The lower lenticles are underlain by dark grey pebbly glauconitic loam with gritty and pebbly 
phosphatic nodules at the base. 



190 yds NE of waterfall 

(v)Grey green pebbly glauconitic loam with patche 3 of 
pure quartz sand, the whole extensively burrowed 
in places. 



(iv)Fawnish pebbly loar 



(iii) Very pebbly grey-green loar 



(ii) Bed of pebbles with 
nodules. 



a few gritty phosphati 



(i) Dark grey gritty glauconitic micaceous clay with 
a few pyrite nodules and wisps of white sand, 
together with brown phosphatic nodules. 



Between path and waterfall 

i) Tough mottled brown-dark grey loam becoming 
coarser and darker upwards with pebbles at top. 



) Dark grey sandy clay and yellowish sand with 1 
of irregular gritty phosphat ic nodules at top and 
small rrard placquettcs at the base. 



iv) Variegated greenish grey-brownish loam. 



i) Coarse glauconitic loam. 



i) Thin ferruginous pale-hearted fine-grained 
c oncreti ons. 



) Coarse glauconitic loam. 



(li)Mixture of ferruginous sand and blackish clay in streaks. 



(i)Coarse dirty yellow sand. 



(v) Concretions of massive ferruginous pebbly grit, with interstitial yellow sand. 



(iv) Yel 1 owi sh sand. 












_ 


(iii) Sligh tl y cemented 


ferruginous pebbly grit 


passing 


i nto 


5 (iv) 


above. 




(ii) Coarse yal lowi sh 


sand qrading into 5 (iii! 













(i ) Ferrugin ou s pebbly cemented grit grading up into 5 (ii). 



Grey sandy clay and dirty yellow sand mixed together in a mottled loam. 



Yellowish bedded sand with glauconite: some thin-bedded and cross-bedded units. Nodules of phosphatised 
grit occur scattered throughout. 



Irregular shaped masses of ferruginous pebbly grit. 



Dirty yellow sand with glauconite. 



300 yds NEof 


he 




270 yds NE of the 


watcrtal 1 




wa t erfall 


Ft 


Ins 




ERjEH 











— 


8 






1 








EB.& 



190 yds NE ol the 
wa terfal I 



2 




3 


3 




— . . .1 

1 3 


5 




1 5 


9 




- 9 


12-18 
3 


333> c35E 


1 8 
— 6 





ffi.S 


1 6 






1 10 






— 8 



ED G3 



(V) 



(iv) 

(ill) 

(ii) 



ti) 



- . . .1 . . 


1 3 


1 5 


— 9 


— 4-11 


1 8 


1 


1 3 


- 9 


1 10 



- 6 

- 9 

- 2 



Fig. 46. Section in Poudingue and Gault in the sea-cliff at Cauville, 
Pays de Caux (Seine Maritime). 



Between poth and 
waterfall 



Ft ins M 



(Hi) 



(ii) 
(i) 





777 / /// 

/ ' ' ' ' • 



' V > r A / / 



EI33 €EE 



- 


9 


— 


4^11 


- 


12-18 


1 





- 


6^12 


2 


9 


- 


6 


2 


4 



— 3 

2 7- 

- 6 

4 6 - 



to6 

Bed 



MIDDLE ALBIAN STRATIGRAPHY 

Li t h ology 



1 1 



10 



First concretionary stone band of the Gaize. 



Silty glauconitic mid-grey clay at base becoming siltier and 
lighter in colour upwards as clay content decreases. 
Phosphatic and pyritic nodules occur scattered throughout. 



Definite break in sequence at the base 



Tough mid-grey, sparsely shelly slightly glauconitic clay, 
silty at base, becoming progressively less silty upwards. 
Scattered shells occur throughout. 



Dark grey-greenish glauconitic loam with scattered shells. 
Thin seams ot light-rinded brown phosphatic nodules occur 
as shown. The basal line contains gritty phosphatic nodules, 
the uppermost line contains septarian phosphatic nodules. 



Dark grey- black greenish tinged glauconitic loam; a little 
pebbly with very scattered gritty phosphatic nodules and 
shells. 

Definite break in sequence ot the base. 



Dark grey-green glau 
nodules, ana shells. 



conitic loam with small phosphatic 



Transitional bed with dark qrey sandy clay content increasinq 
upwards. Dark brown phosphatic nodules at top and bottom. 3 



Brownish sand with a 1-2 inch bed of pure running grit at the 
base. The sand is slightly glauconitic in the lower half, but 
upper half is seamed with glauconitic wisps. 



Hard dark brown very pebbly indurated grit with a few 
phosphatic nodules. 



Mottled brown and dirty yellowish sand with a few brownish 
clay wisps, becoming ferruginous in the upper foot or so. 



Heavily bioturbated mottled loam consisting of a churned-up 
mass of grey sandy clay brown and dirty white sand in 
wisps and pockats. Bed becomes more sandy downwards, 
and contains scattered soft buff phosphatic nodules. 



Ft 



3EE>_(EE 



Ins M 
12- 



10- 



9- 



4 a- 



10. 



7-> 



6- 



1 
10 5- 



3- 



2- 



1 - 



0- 1 



FlG, 47. Section in Poudingue and Gault in the sea-cliff immediately to the NE. and below 
the cliff-top car-park, Octeville, Pays de Caux. 



IN THE ANGLO-PARIS BASIN 107 

matrix. This matrix is very similar to Bed n. Bed 12 at the base shows angular 
pieces of clay indicating heavy erosion of previously deposited clay sediment. The 
bed itself is sandy and contains very fragile but well preserved Inoceramus concen- 
tricus, Anahoplites planus, A. splendens, and Dimorphoplites niobe, indicating the 
niobe Subzone not previously recognised in the Pays de Caux. The loams of Bed 13 
also contain /. concentricus in the lower 1 foot 3 inches (0-38 m.) but apparently no 
ammonites. Post eodentatus Subzone Middle Albian sediments are, therefore, 
present in this area. The Upper Albian sediments probably commence at some level 
within Bed 13. 

(c) Octeville 

This section (text-fig. 47) also has not yielded age diagnostic Middle Albian fossils 
to the writer. It is situated in the cliff immediately to the NE. of the cliff-top car 
park, and again has not previously been described in detail. The lithological correla- 
tion with the sequence at Cap de la Heve and Cauville is, however, more definite than 
that of St. Jouin and Cauville (text-fig. 49). 

(d) Cap de la Heve 

This famous section can be seen high in the cliff on the northern side of the Cap 
(text-fig. 48). It has been studied by a number of workers, but the best recent 
description of the sequence is that given by Rioult (1962 ; 39-42). Cayeux (i960 ; 
25) has recorded Goodhallites goodhalli from the base of the bed here numbered 6, and 
Bed 4 is of mammillatum Zone age. In the Bucaille collection at Rouen, there is a 
single example of Hoplites (H.) preserved in blackish, gritty phosphate stated to have 
come from Cap de la Heve. The preservation is identical to fossils found occasionally 
in Bed 5 which, therefore, probably contains eodentatus and possibly basal lyelli Sub- 
zone fossils in remanie. 

(e) Summary, and comparison with the Isle of Wight 

The lithological correlation of the sections described above is shown in text-fig. 49. 
It can be seen that Lower and Middle Albian sediments reach their maximum develop- 
ment in the area of Cauville. Eodentatus Subzone sediments are present at all 
localities with the possible exception of St. Jouin where it has not been proved. At 
Cauville, the eodentatus Subzone is apparently less condensed, and is followed by 
sediments of the niobe Subzone. To what extent higher Middle Albian sediments are 
present, if at all, is unknown at this time. At Cap de la Heve it appears that Upper 
Albian sediments rest directly upon the residue of basal dentatus Zone age. 

Even if the classification of these sections is unsatisfactory, it is immediately 
apparent that all previous correlations of the ' Argiles du Gault ' of the Pays de Caux 
with the Gault of the Isle of Wight are no longer tenable (p. 42). It appears that the 
sequences in the Isle of Wight and the Pays de Caux are truly out of phase. In the 
Isle of Wight the kitchini Subzone of the mammillatum Zone (Lower Albian) is 



io8 



MIDDLE ALBIAN STRATIGRAPHY 



represented remanie in the basal pebble bed of the Carstone ; in the Pays de Caux it 
is well developed at Cauville. The eodentatus Subzone is represented at the top of the 
Carstone by sediments containing indigenous Hoplites (Isohoplites) ; in the Pays de 
Caux it is present but very condensed even at Cauville. The major difference, how- 
ever, occurs in the Gault. In the Isle of Wight the clays are of lyelli, spathi, and 
probably intermedins Subzones age, followed possibly directly by some orbignyi 
Subzone sediments (Upper Albian) ; the bulk of the loricatus and the whole of the 
lautus Zone being absent. In the Pays de Caux no sediments of any of the Subzones 
mentioned above have yet been detected. However, the niobe Subzone is present at 
Cauville, although absent in the Isle of Wight, and the lowest Upper Albian Subzone 
yet proved is varicosum. 



Bed 


Lithology 


8 


Basal lenticular marly sandstone concretions of the Gaize. s/ 


7 


Light grey micaceous silty malm. 


6 


Mid grey silty micaceous clay becoming a highly glauconitic 
loam by the middle of the bed. 

V 


5 


Very pebbly Ill-graded greenish loam with pebbly phosphatic nodules. . 


4 


Massive indurated blocks of pebbly pale-brown grit in a matrix 
of loose similar material. 


3 


Darker brown Ill-graded pebbly grit with streaks of dark grey 
clay. Lenticles of indurated material occur. 


2 


Loose pebbly brown qrit with little clay. A few scattered phosphates. 


1 


Very coarse brown ill-graded pebbly grit, loamy with streaks of 
grey brown clay in the middle. Large blocks of brown hard 
sand stone, as shown, in lower mottled yellow sand 8. fawn loam. 





Ft 


Ins M 


^zz;:ezz 








1 


6 4 ~ 




6-7 


o 3 " 

2- 




1 


6-8 

0-18 



1- 
6 


(2k 


eB . 







1 


7 


=5&^ ~ "- << 


tc 
2 


7 
0- 



Fig. 48. Section in Poudingue and Gault in the sea-cliff on the N. side of Cap de la Heve, 
100 yds N. of the lighthouse, Ste Adresse, Le Havre, Pays de Caux. 



It is probable that the Isle of Wight and the Pays de Caux belong to two separate 
depositional troughs (p. 142) and do not form one area of deposition as implied by 
previous workers. The sediment of the ' Argiles du Gault ' is a sandy loam rather 
than a clay and small pebbles are present. This together with the Poudingue below 
indicates the close proximity of a shoreline but outcrop and borehole information 
indicate that this could hardly be to the south (see p. 142). 



IN THE ANGLO-PARIS BASIN 



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[io MIDDLE ALBIAN STRATIGRAPHY 

With the completion of the description of the individual sections in England to- 
gether with a brief review of those in France, it is now possible to consider in detail 
the Zonal and Subzonal scheme of the Middle Albian. It is instructive and sobering 
to examine also the history of the development of this particular scheme, not atypical 
of many zonal schemes. There are workers who would insist that zonal schemes 
should be fixed for all time with little regard to future detailed work, or whether the 
scheme is based upon firm foundations. 

IV. DEFINITION OF THE MIDDLE ALBIAN SUBSTAGE AND ITS 
ZONAL SCHEME IN THE ANGLO-PARIS BASIN 

A. Historical background 

The Formation name Gault was accepted in much the same sense by English and 
French geologists within the first half of the 19th Century. The history of its use in 
England was given by Jukes-Browne (1900 ; 14-31). D'Orbigny took William 
Smith's concept, that individual formations could be determined by their fossil con- 
tent, a major step forward when he recognised that fossils characteristic of one litho- 
logical unit occurred in different lithologies and that these, although deposited at 
different localities, were formed at the same time. He erected, therefore, a series of 
chronostratigraphic stages to include these diverse lithologies. Apart from the 
localities mentioned by d'Orbigny (1842 ; 404-5) in his definition of the Albien stage 
(latinized to Albian), he recorded others in 1849 {^ n Geinitz 1849 ; 6-7). Pictet & 
Campiche adopted d'Orbigny 's stage name when they commenced their description 
of the Cretaceous fauna of Ste Croix, Vaud, Switzerland, subdividing it into Albien 
inferiur, moyen and superieur (1858 ; table facing p. 27). 

De Ranee (1868 ; 163-171) was the first worker to describe the Gault section at 
Folkestone in detail. He accepted d'Orbigny's term Albian and divided it into lower 
and upper divisions drawing the boundary between them at what is now known as 
the junction between Beds VIII and IX. The lower division corresponds approx- 
imately, therefore, to Pictet & Campiche's Albien moyen. He recognised eleven beds 
in the Folkestone Gault and referred each to a zone based on its characteristic fossil ; 
employing essentially the characteristic ammonite. Later Price (1874 ; 342-368) 
revised De Ranee's description but neither of these workers on these occasions 
attempted to apply their zonal scheme to sections other than at Folkestone. 

Barrois (1875b ; 707-714) was the first geologist to formally define a zonal scheme 
for the Albian of the Anglo-Paris Basin in the sense that we use today. This idea 
of the application of an index fossil denoting a segment of time and represented by 
different types of sediment, or none at all, differed from that of De Ranee & Price who 
used them merely in a local sense for an actual lithological unit. However, the idea 
crystallised by Barrois for the Albian is implicit in the writings of earlier French 
workers including d'Orbigny. Barrois recognised a tripartite division into : — - 

Zone a Ammonites inflatus 
Zone a Ammonites interruptus 
Zone a Ammonites mammillare 

Of these only the lower two zones were included in the Albian, the Zone a Ammon- 



IN THE ANGLO-PARIS BASIN in 

ites inflatus being included by him in the Cenomanian. Nonetheless, the terms ' Zone 
of Ammonites mammilare ' and ' Zone of Ammonites interruptus ' were first used by 
De Ranee (1868) at Folkestone. Barrois stated that the type area of the interruptus 
Zone was the Aube but he recognised that in this area there was a mixture of what he 
thought to be the fauna of the mammillare Zone (e.g. Douvilleiceras of the clemen- 
tinum group) and that of the interruptus Zone in the clays classified with the latter 
Zone. In 1878 (265, footnote) it was obvious that Barrois was worried by this 
admixture for he states that possibly Ammonites lyelli might have been preferable as 
the index of this zone ; this species being characteristic of the clays of the Gault 
classified with the interruptus Zone from the Aisne to the Yonne. 

Price & Delatour (1879 ; 38-42) concluded that all the beds of the Lower Gault at 
Folkestone had their representatives in the Gault of the Aube, but neither of these 
workers had seen the sections on the opposite side of the Channel. Price and Barrois 
knew each other, and it is significant that Price also refers to a Zone of Ammonites 
lyelli and places it above the Zone of Ammonites mammillaris. Barrois, like many 
of his contemporaries in France, when considering the zonal scheme, was strongly 
influenced by the very full development of the mammillatum Zone, and the eodentatus 
and lyelli Subzones in the Gault of the southern part of the Paris Basin. Although 
Barrois knew the sections at Wissant and Folkestone, and realised that there was a 
break in the succession below the sediments of the inflatus Zone, he does not appear to 
have fully grasped the extent of this gap in the observed sequence in the Aube and, 
therefore, the reason why the sequence in the Aube appeared so different from those 
on each side of the Channel. The observed gap in the southeastern area of the Paris 
Basin involves the equivalent of the greater part of the Lower Gault at Wissant and 
Folkestone, and includes all from the top of the intermedins Subzone to the base of 
the cristatum Subzone. Whether there is a total absence of deposits of this age in 
this area is uncertain (p. 97). 

Jukes-Browne (1900 ; 45) adopted the Zone of Ammonites interruptus but 
restricted it to beds of equivalent age to that of Bed I at Folkestone, the interruptus 
Zone of De Ranee in part and Price. This reading, excluding the equivalent of the 
' Sulphur Band ' brought the English interpretation more into line with the known 
sequence in the Aube. He realised that the remainder of the Lower Gault at Folke- 
stone could not be classified with the interruptus Zone, and he proposed that Beds II 
to VII and their lateral equivalents be included in a Zone of Ammonites lautus. He 
excluded Bed VIII from both the lautus and rostratus zones (the latter being the 
equivalent of Barrois ' Zone a Ammonites inflatus) treating it as a junction bed. 

Because Barrois had classified his Zone a Ammonites inflatus with the Cenomanian, 
Jukes-Browne felt that he could not accept d'Orbigny's name Albien for the stage. 
He had proposed the name Devisian to encompass the Gault and Upper Greensand of 
England (1892 ; 266), but this name clashed with the earlier Oxfordian substage 
name Divesian and the term was replaced by Selbornian (1900 ; 30-31). In reality 
there was no need for a new name and the terms Devisian and Selbornian are 
synonyms of d'Orbigny's Albian. Jukes-Browne's zonal scheme and stage name 
(1900) were employed in England until Spath commenced work on the nomenclature 
of the Albian (1921). 



Gault stufe 

(Albien D'ORB.) 



112 MIDDLE ALBIAN STRATIGRAPHY 

Kilian (1907 ; 62, 67) presented the following scheme influenced probably by the 
work of his pupil Jacob. 

4 Zone der Schloenbachia (Mortoniceras) inflata Sow. sp. 

(mit zwei Subzonen) 
3 Zone des Hoplites dentatus Sow. sp. und Acanthoceras 

lyelli Leym. sp. 
2 Zone des Hoplites tardefurcatus Leym. sp. und Hoplites 

regularis Brongn. sp. 
1 Zone des Parahoplites Nolani Seunes sp. (sog. 
Milletianusschichten) und Douvilleiceras nodosoco- 
statum D'ORB. sp., D. Bigoureti Seunes sp. 

For the first time Lyelliceras lyelli is used formally in a zonal scheme. Jacob's 
thesis was completed in 1907 but not published until the following year (1908 ; 208- 
590, pis. I-VI) when he presented the stratigraphical results of his study of the 
middle part of the Cretaceous of the French Alps and adjoining regions. He divided 
the Albian into the four zones which appear in Kilian's work but in a simplified form. 
His scheme is as follows (1908 ; 296). 

VIb Sous-Zone a Mortoniceras inflatum Sow. sp. 

et Turrilites bergeri Brong. 
Via Sous-Zone a Mortoniceras hugardianum d'Orb. sp. 
V Zone a Hoplites dentatus Sow. sp. 
IV Zone a Hoplites (Leymeriella) tardefurcatus Leym. sp. 
Ill Zone a Douvilleiceras nodosocostatum d'Orb. sp. et 

Douv. Bigoureti Seunes sp. 

The Clansayes horizon (Kilian's Zone 1, Jacob's Zone III) is, therefore, added to the 
Albian. Jacob could not accept Barrois' zone a Ammonites mammillaris because he 
considered that this form was equally abundant in the following horizon (i.e dentatus 
= interruptus Zone), mistaking forms such as Douvilleiceras clementinum (d'Orbigny) 
for ' Ammonites mammillaris '. So, he renamed the zone ' Zone IV a Hoplites 
{Leymeriella) tardefurcatus ' (= Zone of Hoplites tardefurcatus and Hoplites regularis 
in Kilian) . Kilian and Jacob correct the specific name of the interruptus zone to that 
of dentatus, but Jacob does not adopt the index Acanthoceras lyelli. When revising 
the section at Sainte Croix, Vaud, Switzerland, Jacob indicates (1908 ; 291) that 
Zone IV = l'Albien inferieur, V = l'Albien moyen, and VIb = l'Albien superieur of 
Pictet & Campiche (1858). 

Jacob seems to have misread Jukes-Browne (1900) for it was not the term Gault 
that Jukes-Browne could not accept, but the term Albian in the sense of Barrois 
(Jacob 1908 ; 584). The re-inclusion of the Zone a Ammonites inflatus of Barrois 
(Kilian's Zone 4, Jacob's Zone VI) in the Albian, a return to d'Orbigny's original 
definition in terms of lithology, removed the cause of Jukes-Browne's objection to the 
term Albian. Neither Jacob nor Kilian accepted or even mentioned Jukes-Browne's 
Zone of Ammonites lautus. This is understandable when one considers that they 
were strongly influenced by the succession in the Aube (1908 ; 547), with which Price 
& Delatour had given a completely inaccurate correlation of the beds at Folkestone 



IN THE ANGLO-PARIS BASIN 113 

(1879 : I S8° ; 38-42). Moreover, the time span represented by Beds II to VII at 
Folkestone are represented in the Alpine area of France and adjoining Switzerland by 
very condensed deposits in which many horizons are not represented at all. At that 
time the only description of any detail of the section near Wissant was a poor one by 
Barrois (1879 ; 27-28) an abridged version of which was given by Jukes-Browne 
(1900 ; 378-381). Although Barrois had been unable to recognise exactly at Wissant 
the equivalents of the beds numbered by Price at Folkestone, Price stated definitely 
(1879 : 1880 ; 34) that they held good at Wissant. So, according to Price, the 
numbered sequence at Folkestone could be correlated not only with the Aube but 
also with Wissant. The gravity of this error can be judged from the stratigraphical 
account of the French sections given above (p. 80) where it is apparent that a major 
part of the Middle Albian sequence in the Aube is not represented at Wissant and 
vice versa. Although Jukes-Browne agreed with Barrois that the exact equivalents 
of the Beds at Folkestone could not be recognised at Wissant, he perpetuates Price & 
Delatour's erroneous correlation between Folkestone and the Aube (1900 ; 388-9). 
There is no doubt that this strongly influenced subsequent work on both sides of the 
Channel, and this is the reason why French geologists of that period considered that 
the beds at Folkestone included by Jukes-Browne in his Zone of Ammonites lautus 
were of the same age as part of the clays in the Aube included by them correctly in 
the interruptus (dentatus) zone. This led to the time spans, which I now label 
mammillatum, loricatus and lautus Zones, being not recognised at all in Kilian or 
Jacob's zonal schemes. The historical background to the zonation of the Middle 
Albian only will now be considered below. That of the Lower Albian has been dis- 
cussed by Casey (1961a ; 492-499) and the Upper Albian will be discussed elsewhere. 

In Germany the term ' Gault ' included clays of Aptian as well as Albian age (see 
for example Kilian 1907-13). It had been divided into lower, middle and upper 
Gault within the first half of the 19th Century and the question of nomenclatorial 
priorities has been discussed by Spath (1942 ; 670-671). Stolley (1908 ; 246-7) 
recognised in the 'Oberen Gault ' of north Germany the zones already well established 
in France. The ' Zone des Hoplites interruptus ' No. 6 is represented by the 
Minimus Tone and is followed above by the ' Zone der Schloenbachia inflata und 
Puzosia planulata ' No. 7 to include the Flammenmergel. Jacob's scheme con- 
tinued to be used in France (e.g. Tomitch 1918, Ciry 1927, Houdard 1940). 

Spath's work on the classification of the Albian commenced with the following 
arrangement (1921a, 32). 

Gault Up. & Mid. Albian Zones 7 & 6 of Stolley (1908) 

Mammillatus Bed Lower Albian ,, 5 ,, ,, (1908) 

Later in the same year, Spath amplified this classification (1921b ; 311). 

Upper Albian Hor. IX-XIII (Folkestone) Hor. 7 (Stolley) 

(Upper Gault) VI (Jacob) 

Middle Albian f Hor. I-VIII (Folkestone) Hor. 6 (Stolley) 

(Lower Gault) V (Jacob) 
mammillatum bed 

The mammillatum Zone is, therefore, now included in the Middle Albian. In 1922 

H 



ii 4 MIDDLE ALBIAN STRATIGRAPHY 

Spath produced a scheme of ammonite horizons which foreshadowed the zonal scheme 
which appeared the following year (1922 ; 96) . He was far too critical of the previous 
work on the Albian and certainly misread Jukes-Browne, and so in 1923 he dis- 
carded the broad zonal classification of previous workers in favour of the scheme 
shown in Table 2. This zonal scheme was strongly influenced by the sequence at 
Folkestone which Spath had examined in detail (1923a ; 73 : 1923b ; 4 : and see also 
1923c). Unfortunately, in England the sequence between the ' mammillatus Zone ' 
and the 'dentatus Zone ' was at that time very imperfectly known. The ' inaequin- 
odus Zone ' formed a very uncertain taxon, and the ' benettianus Zone ' was par- 
ticularly ill-founded for Spath had no idea of the exact stratigraphical position of the 
lyelli fauna (1923c : 142, see 1926b ; 422), and he was later to classify even high 
spathi Subzone sediments with that Subzone. De Ranee had already used the term 
' benettianus Zone ' in a different sense, and it is unfortunate that Spath ignored the 
sequence in the southern part of the Paris Basin. In effect he restricted the dentatus 
Zone to exclude much of what the French workers understood by this term. He also 
discarded Jukes-Browne's lautus zone replacing it with zones of intermedins, delaruei 
and cornutus, but added a cristatus zone for Bed VIII and its lateral equivalents. 
It was unfortunate that this scheme should have been presented before Spath had 
fully studied the species he had used as indices. In the following two years he had 
to alter this zonal scheme (1924 ; 505 : 1925b ; 31-36), and the year after (1926b ; 
421-2, 425) saw the extensive modification shown in Table 2 (p. 116). 

In 1926 Spath first renamed the lower part of his cornutum Zone, the Zone of 
Euhoplites alphalautus (1926a ; 154 footnote 1), and then later recognised that this 
species was a form found in the varicosum Zone. The major change in the scheme 
given by him later that year (1926b ; 421-2, 425) was the relegation of his zones to 
the rank of subzones in the Table on p. 421. However, the presentation shows 
several inconsistencies for he refers to these subzones in the text as zones. In the 
table he groups the subzones into the ' old zones ' which are in fact those used by 
Jukes-Browne, the names being corrected where necessary. Spath included the 
intermedins Subzone in the dentatus [ohm interruptus] Zone, but Jukes-Browne had 
in fact included Bed II at Folkestone in his lautus zone. Spath recognised, however, 
that the zonal schemes which had been used in Europe were of provincial value only, 
and this was a significant step forward. 

The zonal scheme was further modified during the course of publication of successive 
parts of Spath's Monograph, and one saw the firm readoption of the broader zones. 
He formally presented the various emendations to his earlier scheme in 1941 (1941 ; 
668) and discussed them briefly the following year (1942 ; 671-673) : these are given 
in Table 2. His ' zones ' of 1923 are now emended and reduced to the status of 
Subzones which are grouped into three Zones. The mammillatum Zone is much the 
same as that of Barrois and Jukes-Browne, however, the dentatus and lautus Zones 
do not correspond with the views of earlier workers despite Spath's comment (1942 ; 
672 footnote 3). Is the arrangement given by Spath an improvement ? The junction 
between the dentatus and lautus Zones was placed by Spath at a level where there is 
no significant change in the fauna and the arrangement is quite arbitrary. 

The older zonal grouping of French and English workers such as Barrois and Jukes- 



IN THE ANGLO-PARIS BASIN 115 

Browne was based on a comprehensive knowledge of all the sections then available. 
Even if they did not consider the detail essential to modern work to be of great 
importance, they possessed a broader picture than many later workers, some of whom 
had never examined the sections in the country separated from them by the Channel. 
Superficially Spath's early stratigraphic work appears to have given far greater 
precision to the zonation of the Albian, but this was not so. His zonal scheme was 
introduced without sufficient initial research and suffered greatly by the early need 
for radical alteration, and in the end his zonal boundaries were ill-chosen. He 
appears not to have examined the French sections (1943 ; 722-3), which is most 
unfortunate as it is absolutely essential to have some first-hand knowledge of them. 
There is no question, however, of the immense value of his contribution. Without 
his work on the Albian ammonites the progress made in the study of the stratigraphy 
during the last 25 years would have been very slow indeed. 

Breistroffer (1947) made the first revision to Spath's zonal scheme in an important 
paper comparing essentially the French with the English succession. In this work 
he includes the mammillatum Zone in the Lower Albian and the cristatum Subzone in 
the Upper Albian (1947 ; and Table 2 herein). Casey (1950 ; 270) noted Breistroffer's 
reading of the mammillatum Zone but followed Spath in including it in the Middle 
Albian. Khan (1952 ; 73) produced a useful emendation when he included the 
subdelaruei Subzone in Spath's sense, in the dentatus Zone ; thus placing the junction 
between the dentatus and lauttis Zones at a point where there is some significant 
change in the ammonite funa. Casey, however, again followed Spath in terminating 
the dentatus Zone at the top of the niobe Subzone (1954a ; 264). Milbourne (1956 ; 
241) could not accept a separate subdelaruei Subzone in Spath's sense. He included 
the lower part of Bed IV and its lateral equivalents in the niobe Subzone, and the 
upper nodule bed of Bed IV and its lateral equivalents in the lautus-nitidus Subzone 
recognising that these probably fell within a distinct Subzone. 

The writer in 1958 reviewed briefly the zonal scheme of the Middle Albian, placing 
the zonal boundaries at levels where significant changes in the ammonite fauna 
occurred (1958 ; 160-164). At the same time I drew attention to the difficulties that 
existed in accepting Breistroffer's emendations of Spath's zonal scheme for the 
dentatus and lautus Zones ; except for the position of the cristatum Subzone, these 
have not changed. Subsequently, I proposed formally that the time span repre- 
sented at Folkestone by the upper nodule bed of Bed IV and the basal few inches of 
Bed V and their lateral equivalents be recognised as the Subzone of Euhoplites 
meandrinus (i960 ; 373, 376). The zonal grouping suggested by the author in these 
two papers is shown in Table 1, p. 10. 

In 1961 Casey produced his important revision of the zonal scheme for the Aptian 
and Lower Albian (1961a ; 492-499). He now follows Breistroffer in including the 
mammillatum Zone in the Lower Albian with the exception of Spath's inaequinodum 
Subzone. For this Subzone he proposes a new index, Hoplites (Isohoplites) eodentatus, 
and includes it in the dentatus Zone of the Middle Albian, pointing out that this 
species is the most characteristic ammonite at this horizon in England and France. 
The division between the mammillatum and dentatus Zones and thus the Lower and 
Middle Albian now falls at a distinct change in the ammonite fauna. 



n6 



MTDDLE ALBIAN STRATIGRAPHY 



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IN THE ANGLO-PARIS BASIN 117 

Milbourne (1963 ; 58) places the division between the dentatus and lautus Zones 
above his niobe Subzone (which also includes the subdelamei Subzone of Spath in 
part) . He finds my Subzone of Euhoplites meandrinus unacceptable and substitutes 
for it a Subzone of Dimorphopiites dor is and Euhoplites neglechis. He places the 
subzone in the lautus Zone and so once more the boundary between the two zones is 
placed at a level where there is no significant change in the ammonite fauna. The 
differences of opinion between Milbourne and myself led to a skilful review of the 
zonal scheme by Hancock (1965). Unfortunately two errors were overlooked when 
preparing Table I of Hancock's paper (1965 ; 245). The eodentatus Subzone was not 
recognised by me in 1958 but by Casey (1961), and Spath's lautus-nitidus Subzone 
did not include the time span referred by me to the meandrinus Subzone. The 
meandrinus Subzone formed part of the subdelaruei Subzone in Spath's sense and it is 
important to make this point absolutely clear. 

In 1963 a colloquium on the Lower Cretaceous was held in France ; two very 
important papers being contributed by P. & J. -P. Destombes, and Breistroffer, on 
the zonal scheme of the Albian. These were published in 1965. P., & J. -P. Des- 
tombes propose the following arrangement (1965 ; 266). 

Zone Sous-zone Localite-type 

2 — Lyelliceras lyelli et La Vendue-Mignot 

Hoplites benettianus 

LYELLICERATIEN 

1 — Tegoceras camatteanum Cotes Noires de Moeslains 

Isohoplites eodentatus niv. 5 

This proposition is interesting as it shows in the case of Lyelliceras lyelli an 
independent return to the older view expressed by Barrois, Price, and Kilian, al- 
though it should be noted that Collignon has also used this index (1963 ; 2). P. & 
J. -P. Destombes use a hemeral name for the zone. The use of these terms particu- 
larly by Spath and Breistroffer, is not supported here for they are far too nebulous to 
have any really precise application. Breistroffer's paper (1965 ; 311 & table) 
presents an emendation of his zonal scheme of 1947 and he accepts P. & J. -P. 
Destombes subzonal arrangement for the basal part of the Middle Albian. The 
scheme given by Collignon (1965b) is quite unacceptable. 

The history of this zonal scheme, like that of any other, has been one of progressive 
refinement as knowledge of the succession has improved. Unfortunately, the Albian 
in particular has suffered greatly because of arbitrary decisions concerning the fixing 
of ammonite zonal and subzonal boundaries. These boundaries have been placed 
sometimes without sufficient initial research and have been upheld later purely on 
rather dubious ' historical ' grounds ignoring whether or not there is a significant 
change in the ammonite fauna. A zonal scheme must remain sufficiently flexible to 
take account of new discoveries and better developed sequences. To bang in a 
' golden stake ' at a convenient level in a so-called permanent type-section might 
help the theorist but in reality it only hinders progress towards accurate international 
correlation, and the knowledge of events in the evolution of the Earth that will stem 
from it. 



n8 MIDDLE ALBIAN STRATIGRAPHY 

(B) The Zonal Scheme of the Middle Albian in the Anglo-Paris Basin 
(i) DEFINITION OF THE BASE OF THE MIDDLE ALBIAN 

Towards the top of the mammillatum Zone (puzosianus Subzone) in the Anglo- 
Paris Basin the ammonite genus Pseudosonneratia (s.s. non Casey 1 ) develops as a 
minority element subordinate to such hoplitid genera as Protohoplites s.s., P. (Hemi- 
sonneratia) , Otohoplites, and Sonneratia as well as the common element consisting of 
Douvilleiceras, Beudanticeras etc. The lyelliceratids are represented by very rare 
specimens of Tegoceras. 

Pseudosonneratia of the pusosianus Subzone is the direct forerunner of the simple- 
ribbed non-lautiform species of Hopiites of the dentatus group. Casey (1954b ; 112, 
1961a ; 599) has separated off those species which are transitional between these two 
genera as a subgenus Hopiites (Isohoplites). They are characterised by a partial 
interruption in the strength of each rib along the siphonal line as it sweeps across the 
venter, but no general en echelon offsetting of the ventro-lateral rib terminations 
occurs although the tendency towards this is often apparent. Casey has demon- 
strated that Hopiites (Isohoplites) characterises an horizon above the development of 
the typical mammillatum Zone fauna and corresponds approximately to Spath's 
inaequinodum Subzone (Casey 1961a ; 498 : Spath 1923b ; 73). He included the 
Subzone in the dentatus Zone and subsequent work in France (P., & J. -P. Destombes 
1965 : and herein) and England support this reading. 

The junction between the mammillatum Zone and the eodentatus Subzone has not 
yet been seen in an uncondensed sequence in England. Sediments spanning the zonal 
boundary have, however, been exposed in France at St. Martin in the Pays de Bray 
(p. 100) and at Les Cotes Noires in the Haute Marne (p. 91). At both localities there is 
a marked change in the ammonite fauna with the virtual disappearance of Otohoplites 
at the top of the mammillatum Zone, and the appearance in bulk of Hopiites (Iso- 
hoplites) at the base of the eodentatus Subzone above. In England the available 
exposures of the sequence at this level show only condensed phosphatic nodule beds 
in which the sudden change in the character of the ammonite fauna is probably 
accentuated. The base of the Middle Albian in the Anglo-Paris basin is marked, 
therefore, by the appearance of the genus Hopiites, and as is shown below by the 
appearance of Lyelliceras. 



1 Dr. P. Destombes has collected a very fine ammonite fauna from two localities in the Bois de Perchois, 
Aube, which I have visited in company with him. It is apparent from the material he has shown me 
that Pseudosonneratia iserensis figured by Casey (1965 ; 541 text-fig. 203c, f) is associated in a very little 
condensed sequence — the ' Red Bed ' — at Perchois Ouest with species of Cleoniceras (Neosaynella) and 
Cleoniceras s.s., indicating afloridum Subzone age. It contains species of Otohoplites earlier than any yet 
known in England, showing morphological gradations to the Pseudosonneratia-\ike forms which accom- 
pany them in the same bed. The collection also contains species of Sonneratia with distinct kitchini 
Subzone affinities, although higher in the succession, as well as Douvilleiceras, Beudanticeras and Pro- 
tanisoceras. The fauna of Perchois Est, although preserved in a similar manner, occurs higher in the 
mammillatum Zone sequence. The very important fauna obtained from these two sections is to be 
described in due course by Dr. P. Destombes (see also Destombes 1965). The area is also of interest in 
that at Perchois Ouest the grey clays above the ' Red Bed ' contains an ammonite fauna of distinct 
tethyan aspect. 



IN THE ANGLO-PARIS BASIN 119 

(ii) THE SUBZONAL SEQUENCE (Table i, p. 10) 

(a) Subzone of Hoplites (Isohoplites) eodentatus 

Recognised by Casey (1961a ; 498), although few details were given on that 
occasion, this index replaces the Subzone of Douvilleiceras inaequinoduni of Spath 
(1923a ; 4 : 1923b ; 73 : 1941 ; 668). In England, the Subzone is represented in a 
fossiliferous uncondensed state in the Isle of Wight (p. 52) and at Okeford Fitzpaine, 
Dorset (54). Elsewhere, the known sections exhibit either unfossiliferous sediments 
which probably represent this time span, or remanie phosphatic nodule beds. Future 
deepening of the section at Small Dole, Sussex (p. 35) and at Badbury Wick, Wilt- 
shire (p. 61) may provide a fossiliferous little-condensed sequence from which a direct 
comparison can be made with the succession at St. Martin (p. 100). Maurupt (p. 89) 
and Les Cotes Noires (p. 91) in France. Nowhere in England are the sections at the 
outcrop in this subzone particularly fossiliferous. 

In England, the ammonite fauna consists essentially of species of Hoplites (Iso- 
hoplites) of which H. (I.) eodentatus is typical. It is necessary to bear in mind that 
the tendency to produce the peripheral rib pattern of a typical Hoplites (H.) men- 
tioned already, can be so well advanced that a fragment or even a complete individual 
would have to be referred to Hoplites (H.). This fact alone shows the artificial nature 
of the subgenus Isohoplites. However, these are associated with species in which 
the Pseudosonneratia ventral aspect is still well developed. Apart from the forms 
derived from Pseudosonneratia, there are other Hoplites derived from Otohoplites and 
possibly Protohoplites , and in fact rare specimens of Otohoplites still occur. The 
associated ammonites include Beudanticeras such as B. laevigatum, B. albense, and B. 
santaecrucis, together with Douvilleiceras spp. including D. inaequinoduni. 

Lyelliceras of the camatteanum type, which stands rather in the same relationship 
to Tegoceras on the one hand and Lyelliceras of the lyelli type on the other, as does 
Isohoplites in the hoplitinids, is a great rarity in England. In France it is a reason- 
ably constant and characteristic companion of Hoplites (Isohoplites) and the other 
ammonites mentioned above, and this has led P. & J. -P. Destombes to recommend 
that the Subzone be denned as that of Tegoceras camatteanum and Isohoplites 
eodentatus (1965 ; 265-6). They indicate a type locality, Les Cotes-Noires pres de 
Moeslain, where the subzone is represented by clays in an apparently unbroken 
sequence from the top of the mammillatum Zone to the base of the lyelli Subzone. 
In the lower clays classified with the eodentatus Subzone there is the association of 
Hoplites (Isohoplites) eodentatus and Lyelliceras camatteanum as there is also at 
Maurupt and St. Martin. If one wishes to use a double index then this emendation 
proposed by P. & J. -P. Destombes should be adopted. However, as H. (I.) eodentatus 
is common to this time span throughout the Anglo-Paris basin, the writer employs 
this index only. 

(b) Subzone of Lyelliceras lyelli 

P., & J. -P. Destombes (1965 ; 265-7) have formally proposed that the benettianus 
Subzone in Spath's sense should be redefined as the Subzone of Lyelliceras lyelli & 
Hoplites benettianus. So, the tentative suggestion of Barrois, the bald statement of 



120 MIDDLE ALBIAN STRATIGRAPHY 

Price, the formal proposal of Kilian and the employment of the name by Collignon 
(1963 ; 2) given precision by P., & J. -P. Destombes, has at last taken root. H. (H.) 
benettianus is not a satisfactory subzonal index for in the strict interpretation it may 
be restricted to only a comparatively narrow horizon within the Subzone that it is 
supposed to represent. They have proposed a type locality for this Subzone, the 
Tuilerie Clerc at La Vendue-Mignot, Aube (p. 95), where the Lyelliceras fauna is con- 
sidered to be in the pure state without risk of contamination (in terms of collecting 
fossils that is). In fact the section does not show the relationship between either the 
eodentatus Subzone below or the spathi Subzone above, and there are other objections 
already mentioned. 

The benettianus Subzone was defined without precision by Spath (1923a ; 4, 1923b ; 
73, 1926b ; 422), and was used by him for a range of sediments some of which are 
truly lyelli in age but others have subsequently proved to be of spathi age. It would 
be far more satisfactory if the proposal of P., & J. -P. Destombes were adopted 
modified to a single index of Lyelliceras lyelli. 

In France, the finest section now available in sediments of this Subzone is certainly 
that of Courcelles pres Clerey, Aube (p. 91), although that at Les Cotes Noires is 
probably the most completely displayed in terms of sediments. The best develop- 
ment seen in England was exposed at the Horton Clay pit near Small Dole, Sussex 
(p. 35). A comparison of these two sections brings out the nature of the ammonite 
fauna and the differences to be found between them. Lyelliceras camatteanum and 
its related species of the eodentatus Subzone is connected with Lyelliceras lyelli by a 
series of morphological transitions. Intermediate forms such as Lyelliceras pseud- 
olyelli (Parona & Bonarelli non Spath), Lyelliceras huberianum (Pictet) and L. 
hirsutum (Parona & Bonarelli) form such transitional species. These show the 
transition from the extreme en-echelon arrangement of the ventro-lateral rib termin- 
ations and non-tuberculate siphonal fine characteristic of Tegoceras, to the single ribs 
commencing at the umbilical margin and sweeping without break straight across the 
periphery and bearing mid-lateral, ventro-lateral and siphonal clavi typical of 
Lyelliceras lyelli. These transitional forms occur right at the base of the lyelli Sub- 
zone both at Courcelles and to a limited extent at Small Dole, and on balance it seems 
that the time span in which they existed was of comparatively short duration. Un- 
condensed basal lyelli Subzone sediments are also apparently well developed in the 
Cote d'Or (e.g. Ciry 1927 : Ciry, Rat, Malapris & Nicolas 1965). 

It is apparent that ecological conditions have a marked effect upon the ammonite 
fauna. In deposits of the lyelli Subzone containing a benthonic fauna, the hetero- 
morph ammonites Protanisoceras (P.) barrense and P. (P.) alter notuberculatum are 
common (e.g. Small Dole, and Courcelles) and are as equally characteristic of this 
time span as is Lyelliceras lyelli. Where no benthos is present, or it is very reduced 
in numbers, the heteromorph ammonites are absent or very rare (e.g. the Isle of 
Wight). Lyelliceras lyelli is also affected by ecological conditions in that in beds 
containing abundant Hoplites (H.), Lyelliceras is not common. Casey has already 
noted the tendency to mutual exclusiveness between the earlier members of these 
two families (1957 ; 43-44), although this could in part be due to the hoplitids being 
able to withstand more adverse conditions in the seas of that time. However, the 



IN THE ANGLO-PARIS BASIN 121 

distribution of Beudanticeras laevigatum, B. sanctaecrucis and B. albensis is not 
affected by either of these two factors. In fact the lyelli Subzone may be recognised 
in areas in which sea-bottom conditions produced a sulphide facies in the sediments, 
by the association of Hoplites (H.) spp. and these three species of Beudanticeras. The 
distribution of Douvilleiceras is also not constant. It is rare at Small Dole, although 
very common at the top of the lyelli Subzone at Courcelles. It was also not un- 
common in Bed 14 at Shere (Owen 1963a ; 42). 

The uppermost part of the lyelli Subzone and its junction with the overlying spathi 
Subzone cannot alone be determined by the abrupt disappearance of Lyelliceras lyelli. 
In England, at Small Dole, Sevenoaks (p. 23), and Westerham (p. 31), and at Courcel- 
les (Aube), there are clays just below the spathi Subzone which still contain lyelli 
Subzone species of Beudanticeras, Douvilleiceras (Courcelles only), and Protanisoceras 
(P.), but Lyelliceras is absent. It is recommended that these sediments be included 
in the lyelli Subzone for the significant change in the ammonite fauna occurs at the 
top of them where all the non-Hoplites {H.), lyelli Subzone ammonite species vanish 
abruptly from the sequence. In the English and French sections mentioned here 
there is no apparent break in deposition and no change in facies. Protanisoceras (P.) 
still occurs in the spathi Subzone but it is very rare, and, in effect, the heteromorphs 
are almost exclusively species of Hamites (H.) with subordinate Metahamites. There 
is no major change in the species of Hoplites (H.) in the transitional period between 
the lyelli and spathi Subzones. The transitional sediments at the top and bottom 
of the lyelli Subzone are of no great thickness in well developed sequences. Even 
slight condensation produces an apparent sharp change in the ammonite fauna at the 
subzonal boundaries. 

(c) Subzone of Hoplites (Hoplites) spathi 

H. (H.) spathi in its typical form occurs in this subzone but it is not very common, 
although there is no dearth of closely related forms. It is possible that Spath 
selected this species (1941 ; 668 : 1942 ; 672, under the preoccupied name bonarellii) 
because in terms of ornament it stands mid-way between the more discoidal finer 
ribbed species of the dentatus type and the inflated coarsely ornamented forms of the 
maritimus-rudis group. The name dentatus-spathi Subzone is in any case too well 
established in the recent literature both sides of the Channel to justify altering it, 
except to reduce it to a single index of H. (H.) spathi. 

The Subzone is well developed in England and the section at Small Dole is par- 
ticularly important as it shows in a very fossiliferous little condensed sequence the 
junction with the lyelli Subzone below and, albeit imperfectly, the intermedius Sub- 
zone above. In France, the junction with the lyelli Subzone is seen in an uncon- 
densed sequence at Courcelles, and the junction with the intermedius Subzone again 
in an uncondensed sequence at Revigny-sur-Ornain (p. 88). The ammonite fauna 
consists very largely of species of Hoplites (H.) of which the general evolutionary 
characteristics of stratigraphical value have been given by me (Owen 1963a ; 49). 
The very small percentage minority element in the fauna provides a good list of 
genera and species (p. 152) some of which are of value in correlation with other faunal 
provinces. 



122 MIDDLE ALBIAN STRATIGRAPHY 

The division between the lyelli and spathi Subzones has been discussed above. The 
sediments representing the transitional period between the spathi and intermedins 
Subzones do not contain ammonites in the area of the Weald except at Petersfield 
(p. 34). At present it cannot be demonstrated in any one section in England, how- 
ever, the section at Osmington (p. 51), Dorset, and Caen Hill, Devizes (p. 60) show 
the extreme top of the spathi Subzone and the extreme base of the intermedins Sub- 
zone respectively. Bed 2 at Osmington contains abundant high spathi Subzone 
Hopiites (H.) together with rare early forms of Anahoplites of the intermedins group 
such as A. osmingtonensis and A. grimsdalei spp. nov. In Bed 7 at Caen Hill, 
Hopiites (H.) has become very subordinate to slightly later forms of Anahoplites such 
as A. evolutns which are in turn earlier than Anahoplites intermedins and its con- 
temporaries. A . evolutns is also known from Bed C at Hunstanton. These sediments 
containing A. evolutns are here considered to mark the base of the intermedins 
Subzone. 

In France, fragments of Anahoplites osmingtonensis and A. evolutns occur in Bed 4 
at St. Florentin (p. 97), a phosphatic nodule bed containing en melee material derived 
from both the spathi and intermedins Subzones. At Revigny-sur-Ornain (p. 88) 
these transitional sediments are uncondensed but the ammonites are mainly crushed 
flat. At Wissant sediments deposited during this period have not yielded ammonites. 

There is no difference between this interpretation of the spathi Subzone and the 
views of French geologists (e.g. Breistroffer 1965 ; 313). From this account it is now 
obvious that the parochial view expressed by Milbourne (see Hancock 1965 ; 246-7), 
fixing the top of the spathi Subzone at an horizon of condensation in a comparatively 
small area of the outcrop in the northern Weald, is totally unacceptable. The record 
of Anahoplites intermedins a foot or two above the spathi nodule bed at Folkestone 
(Bed I (vi) ) by Casey (in Hancock 1965 ; 247) is here considered to be a misidentifica- 
tion of the finely-ribbed H. (H.) dentatus densicostata Spath which is just as common 
in the higher part of the Subzone. 

(d) Subzone of Anahoplites intermedins 

Although there is some condensation at Folkestone, this section (p. 14) provides the 
best sequence yet known in this Subzone recognised by Spath in 1923. The sequence 
at Small Dole is the least condensed and also shows, albeit imperfectly, the junction 
with the spathi Subzone below, and also the junction with the niobe Subzone above ; 
however, the fauna is crushed flat. The junction with the spathi Subzone has been 
discussed above. The lowest part of the Subzone with Anahoplites evolutns has not 
yet been discovered in the Weald and so at Folkestone the earliest intermedins Sub- 
zone sediments containing ammonites yield Anahoplites intermedins and A. praecox. 
In France the section at Wissant shows an imperfect development of sediments 
representing this Subzone, but at Revigny-sur-Ornain, and at Courcelles the lower 
part is well developed. 

The characteristic ammonites of this time span are the group of Anahoplites 
typified by A. intermedins. The ammonite fauna of the Subzone as a whole is more 
diverse than that of the spathi Subzone below. Hopiites (H.) is greatly subordinate 
to the other genera, but the group which had produced rare Euhoplites by the top of 



IN THE ANGLO-PARIS BASIN 123 

the spathi Subzone is well represented by forms such as E. loricatus, E. microceras, E. 
subtabtdatus and E. pricei. Early forms of Dimorphoplites including D. niobe 
(praemutation) occur sparingly, and some of these show a tendency to the lautiform 
ribbing not generally developed again in the genus until the meandrinus Subzone. 
Heteromorphs are not uncommon and consist not only of Hamites (H.) spp., but also 
of species of Protanisoceras (Heteroclinus). The early binneyitid Falciferella mil- 
bonrnei can be abundant at certain horizons. Apart from the endemic forms, there 
is a much rarer element represented by specimens of Uhligella, Tetragonites, Des- 
moceras, Eubrancoceras and Pseudhelicoceras (e.g. P. subcatenatum Spath.) 

The upper limit of the Subzone is marked by the quite sudden decline of Ana- 
hoplites of the intermedhis group, which do not extend into the niobe Subzone above. 

(e) Subzone of Dimorphoplites niobe 

The Subzone was recognised by Spath (1924 ; 505), it having previously formed 
part of his intermedins Zone (1923a, b). It has been considered to be of local value 
(Spath 1942 ; 672) but in fact it is of widespread occurrence. Sediments of this time 
span are relatively uncondensed at Folkestone and to a lesser extent at Small Dole. 
Elsewhere in the Weald the sequence is somewhat condensed, where indeed it has 
escaped basal Upper Albian planation. Outside the Weald, it is developed in the 
Leighton Buzzard district. In France, the Subzone may be developed at Wissant 
(p. 83), but the only locality at which it can be proved with certainty is Cauville, 
Seine Maritime (p. 107). The restricted development of the niobe Subzone led Breis- 
troffer in effect to include it in the intermedins Subzone (1947 ; 44, 1965 ; table 
opposite p. 312) but his view was probably also influenced by Spath (1942 ; 672). 

The ammonite fauna is a curious one in that it has no species restricted to it, yet 
it is distinctive. Anahoplites intermedhis and its allies have gone, and Dimorphoplites 
niobe, A. planus and A. splendens are the characteristic species. The upper limit 
of the 'Subzone occurs immediately below the appearance of Mojsisovicsia in the 
sequence. 

(f) Subzone of Mojsisovicsia subdelaruei 

Originally indexed by Spath (1923a ; 4, b ; 73) using ' Dipoloceras ' delaruei. He 
realised later that this species did not occur in this time span, and it has been found 
subsequently in the spathi Subzone. The Subzone as originally defined included 
sediments now classified with the meandrinus Subzone. The Subzone is represented 
by uncondensed deposits at Ford Place, Wrotham (p. 22) and at Sevenoaks (p. 25), 
but elsewhere in England where deposits of this age are preserved they are condensed. 
In France, they are known only in a condensed state (e.g. Bed 11 at Wissant). 

Apart from the species of Mojsisovicsia, a genus which last made its appearance 
in the Anglo-Paris basin in the spathi Subzone, and which in the subdelaruei Subzone 
shows marked evolutionary changes, the hoplitinid fauna shows more diversity of 
form than in the niobe Subzone below. Mojsisovicsia subdelaruei appears at the 
base of the Subzone and evolves to M. remota at the top. The occurrence of Dimor- 
phoplites niobe led Milbourne to unite this time span with the niobe Subzone (1956 ; 
241, 1963 ; 64), but on balance this incursion of keeled ammonites into the Anglo- 



i->.| MIDDLE ALBIAN STRATIGRAPHY 

Paris basin dictates that it be kept separate. The species of Euhoplites show little 
difference to those of the niobe Subzone below, but Dimorphoplites commences to 
differentiate towards the forms seen in the meandrinus Subzone above. 

The upper limit of the Subzone coincides with the last appearance of M. remota. 
However, Mojsisovicsia is not at all common at this height and it is necessary to use 
the grade of development shown by the species of Euhoplites and Ditnorphoplites at 
the base of the meandrinus Subzone, discussed below. 

(g) Subzone of Euhoplites meandrinus 

This time span, included by Spath in his subdelaruei Subzone, was indexed by 
the writer (Owen i960 ; 373, 376). Its separate nature was recognised by Milbourne 
(1956 ; 241), who included it provisionally in the nitidus Subzone, and by the author 
(Owen 1958 ; 162). Unfortunately, there is an error in Hancock (1965 ; 245 Table I) 
for this Subzone was not included by me in the nitidus Subzone, that is, in the basal 
Subzone of the lautus Zone as restricted by me in 1958. Milbourne (1963 ; 65) 
indexed this Subzone with his ' species ' Euhoplites neglectus (which on examination 
of the type material proves to be a synonym of E. meandrinus) together with Dimor- 
phoplites doris. My objections to this emendation were set out in Hancock (1965 ; 
247) and this clash of opinion led to a mistake in the zonal scheme given by Kaye 
(1965 ; 220). 

The Subzone is characterised by E. meandrinus and closely related forms such as 
E. cantianus, E. loricatus (late mutation), and E. beaneyi which still possess the 
deeply sulcate venter characteristic of the genus in the preceding subzones. The 
late mutation of E. subtuberculatus tends to show the development of the channelled 
venter characteristic in the lautus Zone on its outer whorl, but the inner whorls are 
still sulcate. The pattern of ribbing on most of these species is transitional to that 
of the typical lautus Zone species. Dimorphoplites has become more diverse in form 
and apart from the typical meandrinus Subzone species such as D. doris and D. pinax, 
there are the early mutations present of the species which occur commonly in the 
lautus Zone above but they are greatly subordinate in numbers. Mojsisovicsia is 
absent from this time span. 

In England, the meandrinus Subzone is present in an uncondensed sequence at the 
Horton Clay Pit, Small Dole (p. 40). At the Sevenoaks Brick Works (p. 25) and 
further east in Kent, the sediments are condensed to a variable extent. Its known 
representation is confined to eastern England. In France, the only locality at which 
the Subzone is known to be represented at this time is at Wissant in Bed 11 which 
also contains material derived from subdelaruei Subzone sediments and nitidus Sub- 
zone sediments as well. 

At Small Dole, and at Ford Place, in particular, the sudden change from a sulcate 
to a channelled venter in the species of Euhoplites can be well seen in sediments which 
are uncondensed. This marks the base of the overlying nitidus Subzone. 

(h) Subzone of Euhoplites nitidus 

Spath originally included Beds V-VII at Folkestone in a zone of Dipoloceras 
cornutum (1923a ; 4, b ; 73) but having realised the rarity of that species he divided 



IN THE ANGLO-PARIS BASIN 125 

this zone into two ; the zone of Euhoplites alphalautus (1926a ; 154 footnote 1) to 
include Beds V and VI, and that of Anahoplites daviesi to include Bed VII (see also 
1925b ; 34-35). Within a few months he realised that E. alphalautus was a form of 
the varicosum Subzone, and substituted for it Euhoplites lautus and E. nitidus (1926b ; 
425). Breistroffer (1965 ; table opp. 312) has grouped the nitidus and daviesi Sub- 
zones as Subzone of nitidus -\- cornutum -\~ daviesi. This view is probably influenced 
by the section near Wissant where the daviesi Subzone was thought to be present, but 
where it is now known to be absent (p. 85). 

In England, the best known development is at Folkestone where the relationship 
with the meandrinus Subzone below and the daviesi Subzone above is well seen (p. 15). 
In France, the Subzone is well represented at Wissant but the sediments there are 
marked by erosion levels at the base and the top (p. 84). The Subzone is not known 
to be represented elsewhere in France at this time. The base of the Subzone is 
marked by the general adoption of a channelled venter by the various species of the 
genus Euhoplites. The ammonite fauna of the Subzone has been discussed by Owen 
(1958 ; 154) and Hancock (1965 ; 246) and there is nothing further to add except that 
the top of the Subzone is now drawn at Folkestone at the level within Bed VII 
immediately below the first appearance of Anahoplites daviesi in the sequence. 

(i) Subzone of Anahoplites daviesi 

This Subzone recognised by Spath (1925b ; 35, 1926a ; 153-4) is characterised by 
Anahoplites of the daviesi group. There is virtually no difference in the accompany- 
ing ammonite fauna in England, but these very characteristic species of Anahoplites 
have a wide geographical range in this time span, and on this point alone the Subzone 
should remain separate from that of E. nitidus. Breistroffer's grouping (1965 ; table 
opp. 312) is not acceptable, and the British reading should be adhered to (e.g. Owen 
1958 and Hancock 1965 ; 245, 246). 

The Subzone is best developed at Folkestone although it is present in uncondensed 
sediments elsewhere in Kent and Sussex (Ringmer). However, at Folkestone there 
are clays representing horizons higher than any known elsewhere outside the U.S.S.R. 
Even at Folkestone the top of the clays of Bed VII representing this Subzone are 
planed-off and the basal nodule bed of Bed VIII contains material of late daviesi 
Subzone age. At Wissant, the lower part of the cristatum Subzone (the partial 
equivalent of Bed VIII (i) at Folkestone) is represented by clays. Unfortunately these 
rest non-sequentially upon sediments of nitidus Subzone age (p. 85) and neither at 
Wissant nor elsewhere in France at this time have sediments of daviesi Subzone age 
been proved. The development of the Subzone in Russia is mentioned later (p. 132). 

The upper limit of the Subzone can, however, be determined by reference to Bed 12 
(v) at Wissant which contains no Anahoplites of daviesi type but in which Dipoloceras 
bouchardianum and Beudanticeras beudanti make their appearance marking the base 
of the cristatum Subzone. In this bed also there occurs the morphological transition 
from Inoceramus concentricus to the shell form I. sulcatus (p. 85). 



126 Ml DOLE ALBI AN STRATIGRAPHY 



(iii) THE POSITION OF THE SUBZONE OF DIPOLOCERAS 

CRISTATUM 

The junction of the Lower with the Upper Gault at Folkestone is marked by two 
seams of phosphatic nodules separated by a few inches of clay (p. 15). This junction 
bed (Bed IV of De Ranee 1868, and Bed VIII of Price 1879, 1880, Jukes-Browne 1900 
and subsequent workers) has always been included in the Lower Gault. However, it 
has long been recognised that the fauna is a transitional one containing elements 
characteristic of the beds below and above. The bed formed the zone of Ammonites 
beudantii of De Ranee, and that of Ammonites cristatus of Price. Jukes-Browne 
(1900 ; 45) did not include the time span represented by Bed VIII in his zone of 
Ammonites lautus. Spath, however, placed his cristatum ' zone ' in the Middle 
Albian (1923a, b) and later relegated it to subzonal rank and included it in the lautus 
Zone in his sense (1926b ; 425). This classification has been followed by later Eng- 
lish workers (e.g. in Hancock 1965 ; 245, 246). Breistroffer (1947 ; 48, 68) included 
the Subzone in the Upper Albian where it stood in isolation. The author stated that 
more research would have to be carried out before a final decision could be made on 
the position of the cristatum Subzone (1958 ; 164). However, in the meantime, 
Breistroffer's recommendation (see also 1965 ; table) has been accepted by other 
workers such as Collignon (1963 ; 2) for the sequence in the Malagasy Republic, and 
Young (1966 ; 15) for the succession in Texas, and in England by Melville (in Smart 
et ah, 1964 ; 7). 

Although Bed VIII contains a fauna which on balance links it with the Upper 
Albian, its lower nodule bed includes an important Middle Albian element derived 
from sediments of daviesi Subzone age. One of the principle objections to placing 
the cristatum Subzone in the Upper Albian is that hitherto it has meant placing the 
Middle-Upper Albian junction at a level of erosion. However, it is now known that 
the basal part of the cristatum Subzone is represented in an uncondensed sequence in 
Bed 12 (v) near Wissant. This fact removes any objection that the writer might 
formerly have held against placing the Subzone in the Upper Albian, and I now 
recommend that it be included in the Upper Albian to form the basal Subzone of the 
inflatum Zone. 

In Bed 12 (v) at Wissant we can see the incoming of a basal Upper Albian fauna in 
an uncondensed sequence (p. 85) . The change in Inoceramus from a concentricus to a 
sulcatus form has already been mentioned. Beudanticeras beudanti appears together 
with D. bouchardianum. These forms are all known from Bed VIII (i) at Folkestone. 
Bed 13 at Wissant contains en melee material derived from the equivalent of Bed VIII 
(ii) & (iii) at Folkestone together with the lower part of Bed IX up to and including 
the horizon of Euhoplites inornatus. In truth Bed 13 at Wissant forms the base of 
the Upper Gault in our sense as well as that of our French colleagues. However, they 
consider it to be the direct equivalent of Bed VIII, whereas it is in fact the product 
of one period of erosion which occurred at Wissant later in the cristatum Subzone, 
while at Folkestone there were essentially two phases of erosion at earlier dates 
within this Subzone. It has been, up to now, the view of our French colleagues that 



IN THE ANGLO-PARIS BASIN 127 

all the Gault below Bed 13 of Destombes was of Middle Albian age, but it must now be 
recognised that Bed 12 (v) below is in fact of basal cristatum Subzone age. 

The fauna of the cristatum Subzone on balance, bearing in mind that a late daviesi 
Subzone element is present in Bed VIII (i), has its most important faunal link with 
the beds above rather than those beneath. The very characteristic lower Upper 
Albian bivalve form /. sulcatus develops in the basal part of the cristatum Subzone and 
ranges up to the top of the orbignyi Subzone. Towards the top of the Middle Albian 
daviesi Subzone, extreme forms of Anahoplites of the daviesi group occur which are 
close to, but still generically distinct from Epihoplites (including Metaclavites). At 
the same point in time species of Enhoplites and Dimorphoplites modify towards those 
of the cristatum Subzone. The hoplitinids are almost completely dominant, the onfy 
Mojsisovicsiinid being Dipoloceras cornutum which is very rare. In the cristatum 
Subzone above we see the introduction of an important non-hoplitinid element in the 
ammonite fauna. In fact many of the subfamilies last well-represented in the Anglo- 
Paris basin in lyelli Subzone times appear once again in consort, and as before are 
subordinate to the hoplitinids. 

Euhopiites is well represented but the species are essentially different to those of 
the Middle Albian below, and are, moreover, more closely linked to those of the 
orbignyi Subzone. This genus survives until the auritus Subzone and it is interesting 
to find that a largely unfigured varicosum Subzone fauna in the Leighton Buzzard 
area contains forms which are morphologically closer to those species of Bed V-VII 
at Folkestone than to those of Bed VIII. Dimorphoplites in the strict sense does not 
survive the cristatum Subzone, its nitch being filled by Epihoplites (including Meta- 
clavites Casey) . It is quite possible that the ecologic factors which caused Inoceramus 
concentricus to develop the strengthened shell from of i". sulcatus, also brought about 
changes in the morphology of the endemic hoplitinids during the clearly unsettled 
physical conditions in the cristatum Subzone sea. 

The non-hoplitinid element in the ammonite fauna is subordinate but highly 
characteristic of this Subzone and foreshadows the major development of the branco- 
ceratinid and mortoniceratinid ammonites which occurs at the base of the orbignyi 
Subzone in the sense used here. Hysteroceras is represented by H. pseudocornutum, 
H. capricornu, and H. simplicicosta, forms which are transitional from the earlier 
Eubrancoceras. An early mutation of H. orbignyi does in fact occur in the cristatum 
Subzone, but the only species of Mortoniceras known is M. rigidum although the 
generic position given it by Spath is uncertain. Dipoloceras itself, the characteristic 
genus of this time span, probably gave rise to Mortoniceras but the picture is not 
clear at this time. The Lyelliceratidae is represented by Neophlycticeras which also 
ranges into the orbignyi Subzone but it is rare. Beudanticeras represented in the 
cristatum Subzone by the type-species B. beudanti and forms such as B. subparandieri, 
also continued on into the orbignyi and higher Upper Albian Subzones. 

The cristatum Subzone must also include the time span represented within the 
sediments of the basal part of Bed IX at Folkestone up to the level at which Hyster- 
oceras and Mortoniceras characteristic of the orbignyi Subzone suddenly became 
dominant. This just excludes the horizon of Euhopiites inornatus which is of wide- 
spread occurrence in England and forms a good marker for the base of the orbignyi 



I2S Ml DDLE ALBIAN STRATIGRAPHY 

Subzone. The cristatum Subzone as here defined, therefore, includes sediments 
grouped with the Upper Gault. 

As Breistroffer has pointed out (1947 ; 48-50), Dipoloceras cristatum and the other 
contemporary species of this genus are of widespread occurrence. They are known 
in sequences as far removed from each other as the Anglo-Paris basin, the Malagasy 
Republic and Zululand, Russia and Texas, that is, in more than one ammonite 
faunal province. The well-marked period of erosion of Middle Albian sediments in 
the Anglo-Paris basin which occurred during the cristatum Subzone, is just as well 
marked in the Malagasy Republic (Besairie & Collignon 1956). Although not 
specifically stated by Young (1966) there are signs of a similar break in Texas. It is 
also possible that there is a break in the sequence in Peru (Benavides-Caceras 1956). 
In an entirely different faunal province still, the occurrence of Gastroplites cantianus 
in Bed VIII at Folkestone and in the lower part of the Gastroplites Zone in Canada is 
extremely important (e.g. Jeletsky 1964 ; Table 1, 1968). In Canada there is a 
definite break in the ammonite sequence although apparently not in the sedimentary 
sequence (Jeletsky in litt.), for the mcconneli Zone which contains genera such as 
Arcthoplites, Cymahoplites and Cleoniceras, both known from the mammillatum Zone 
of the old world (Casey 1961c ; 167) is definitely of Lower Albian age. A similar 
ammonite faunal gap involving the whole of the Middle Albian appears to exist in 
Alaska (Imlay i960 : 1961) and California. Imlay's Cleoniceras (Grycia) presents no 
difficulty here because it does not possess umbilical bullae and almost certainly 
belongs to Beudanticeratinae. In effect, by taking the base of the Upper Albian to 
coincide with the base of the cristatum Subzone and its provincial equivalents, it is 
possible to arrive at a common point of division between the two substages capable of 
recognition in the local successions of each county. 

(iv) THE ZONAL GROUPING (Table 1, p. 10) 

(a) The Zone of Hoplites (H.) dent at us 

As defined here this Zone comprises the Subzones of H. (I.) eodentatus, L. lyelli and 
H. (H.) spathi. This represents virtually the total range of the closely related 
morphological group of Hoplites represented by the index species H. (H.) dentatus. 
In the eodentatus Subzone, this species is not typically developed, but in fact H. (I.) 
eodentatus is a direct transition between the earlier Pseudosonneratia and H. (H.) of 
the dentatus group. This group dies out at the top of the spathi Subzone, although 
Hoplites (H.) continues onwards into the loricatus Zone above. With some modifi- 
cation, this is almost a return to the old concept of the interruptus Zone in Barrois' 
and Jukes-Browne's sense. 

The Zone is geographically widespread represented in sediments both condensed 
and uncondensed. The hoplitinid faunal province by the spathi Subzone can be 
shown to have extended from the western border of asiatic Russia, south to the 
northern margin of Tethys now represented in the Caucasus mountains. The 
boundary then runs along the northern side of Tethys westwards to France. The 
land area flanking the east side of the Atlantic rift system which existed at this 
time (cf. Carey 1958) apparently formed the western boundary, although the situation 



IN THE ANGLO-PARIS BASIN 129 

in Greenland is not yet clear. In a similar manner the primitive Arctic Ocean may 
have formed the northern boundary, for Hoplites is not yet known from Canada, 
Alaska or Japan. The province, therefore, consists of the shelf seas of Europe. In 
the lyelli Subzone especially, there are important links with adjoining ammonite 
faunal provinces in which Hoplites (H.) is as yet unknown. These links are discussed 
in greater detail below. 

(b) The Zone of Euhoplites loricatus 

This Zone comprises the Subzones of A. intermedins, D. niobe, M. subdelaruei and 
E. meandrinus. It is almost the total range of E. loricatus which is typical of the 
group of Etihoplites with sulcate rather than channelled venters seen late in the lautus 
Zone. Deposits of this Zone, with the exception of the basal part of the intermedins 
Subzone, are of very limited occurrence in the European province. This is probably 
due to erosion in the early part of the Upper Albian which apparently produced a 
fairly general hiatus involving the loricatus and lautus Zones throughout much of 
Europe except in the deeper basins. It could be argued that there is no point in 
dividing Jukes-Browne's original lautus Zone into two parts, but the morphological 
change in Euhoplites is quite striking at the level at which the writer has drawn the 
base of the lautus Zone. Although the change in the remainder of the ammonite 
fauna is not quite so clear cut, nonetheless it does occur at about the same point in 
time. The ammonite fauna of the loricatus Zone is grosso modo sufficiently distinct 
for it to be capable of definite recognition at zonal rank. Spath placed the division 
between the dentatus and lautus Zones in his sense at the top of the niobe Subzone 
where in fact there is no significant change in the ammonite fauna. This quite 
arbitrary and meaningless arrangement is firmly rejected here. 

The intermedins Subzone has as great a geographical range as the spathi Subzone 
of the dentatus Zone but known sediments of the niobe, subdelaruei and meandrinus 
Subzones are preserved in only a very limited area, that of eastern England and 
northern France. Links with other ammonite faunal provinces are very few and 
mainly with the tethyan belt. 

(c) The Zone of Euhoplites lautus 

The lautus Zone as now defined consists of two Subzones ; that of Euhoplites nitidus 
and that of Anahoplites daviesi. It is essentially the total range of Euhoplites lautus, 
and the contemporary species of this genus with their well-marked clean cut ventral 
channel. The base of the Zone as indicated above is defined by the quite sudden 
change in the peripheral aspect of Euhoplites. The top is defined by the appearance 
of Dipoloceras bouchardianum and Beudanticeras beudanti indicating the base of the 
cristatum Subzone. 

Deposits of the nitidus Subzone are of very limited known geographical extent. 
They are known from eastern England and northern France, and apparently occur 
also in Poland, but these are probably only remnants which survived the basal Upper 
Albian erosional movements. The daviesi Subzone can definitely be identified in 
Russia (Mangyshlak Peninsula) but this is the only area outside the eastern Weald of 
England that deposits of this Subzone have as yet been recognised. Russian 



130 MIDDLE ALBIAN STRATIGRAPHY 

workers (e.g. Glasunova 1953a ; 18) have recognised above the dentatus Zone, which 
in effect is equivalent only to the spathi Subzone, a Subzone of Anahoplites asiaticus. 
It is apparent that this is, in part, of intermedins (e.g. Kopet Dagh, Mangyshlak), and 
in part of daviesi Subzone age (e.g. Mangyshlak). Anahoplites asiaticus and A. 
transcaspius Glasunova (1953a) look like early intermedins Subzone Anahoplites com- 
parable to, although perhaps not specifically identical with species known in the 
uppermost spathi and basal intermedins Subzones of England and France. A some- 
what different scheme has been proposed by Sokolov (1966) and this is discussed 
below (p. 132). 

V. LINKS WITH OTHER FAUNAL PROVINCES 

The following is a brief review of the known links between the hoplitinid and other 
f aunal provinces at certain levels in the Middle Albian. A vast amount of work still 
remains to be done to determine the degree of representation of Middle Albian 
sediments throughout the whole surface of the Earth and so to determine accurately 
the boundaries of the various faunal provinces. It is becoming apparent, however, 
that sediments of Middle Albian age are far more restricted in occurrence than those 
of the Upper Albian, and in many areas where they both occur, there is often evidence 
of a hiatus between them. Basal Upper Albian sedimentation in widely scattered 
places on the Earth commenced after a period of erosion (e.g. Europe, and the 
Malagasy Republic), or they transgress onto very much older surfaces (e.g. Africa). 
The fauna itself shows evidence of unstable conditions at the base of the Upper 
Albian (p. 127). Whether Middle Albian sediments were deposited over a widespread 
area of the Earth only to be removed largely by subsequent erosion is a matter of 
conjecture. Here, however, we are concerned only with an outline sketch of the 
boundaries of our province and at what definite levels it is possible to correlate with 
adjoining provinces. 

A. The boundaries of the hoplitinid province (text-fig. 50) 

The westward boundary of the hoplitinid province during the Middle Albian was 
formed by the massifs of Morvan and Armorica. These separate the European shelf- 
sea from the narrow sea-way connected with the Tethyan belt which was then the 
'Atlantic' (Carey 1958 ; Bullard et al., 1965). No species of Hoplites, Enhoplites, 
Anahoplites or Dimorphoplites have yet been found in the United States of America 
and Canada. However, there are tantalising references to a typical hoplitinid fauna 
in argillaceous sediments in the coastal area N. of Scoresby Sound, E. Greenland 
(Spath 1946 : Donovan 1949, 1953) which demonstrate that this area also is to be 
included in the province. If E. Greenland is brought back to its apparent middle 
Cretaceous position, the coast N. of Scoresby Sound is approximately opposite the 
northern outlet of the present day North Sea basin. 

At the present time no information is available about Middle Albian sediments in 
the North Sea Basin, but the evidence from the eastern margin of England and from 
deep borings in Holland suggest that sediments of Middle Albian age thicken towards 
at least the south central part of the Basin. The Middle Albian sediments of Ger- 



IN THE ANGLO-PARIS BASIN 



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132 MIDDLE ALBIAN STRATIGRAPHY 

many belong to the hoplitinid province and these extend through Poland (e.g. 
Cieslinski 1959) into Russia, although they are largely concealed by later rocks. In 
this respect it is interesting to note that Ravn (1925) has figured ammonites from 
the Cenomanian basal conglomerate on the Baltic Island of Bornholm. These indi- 
cate not only that elements derived from the tardefurcata and mammillatum Zones are 
present en melee with Cenomanian ammonites but also his Sonneratia Baylei (pi. Ill, 
fig. 6a, b) looks like an Anahoplites suggesting the possibility of Middle Albian 
material also being represented in the deposit. This paper seems to have escaped 
the attention of previous English workers (see also 0dum 1928 ; 44-5), and throws 
light on the provenance of the glacial erratics described by Skeat & Madsen (1898) 
from the Jutland drift. 

The hoplitinid province in the Middle Albian may not include all of Russia in 
Europe, but it certainly extends as far east as the southern Urals and the eastern 
border of the Caspian Sea south to the Kopet Dagh in the border region with Iran. 
The area of Daghestan flanking the western side of the Caspian, and the area between 
the Mangyschlak Peninsula and the Kopet Dagh is of considerable interest. From 
the ammonites figured by Semenov (1899), Sinzov (1909 : 1915) and Glazunova 
(1953a, b) together with the recent stratigraphical work carried out by Sokolov (1966) 
it is apparent that Middle Albian sediments are well developed in this area. Sedi- 
ments of lyelli Subzone age appear to be absent, but there is a good fauna of Hoplites 
(H.) spp. indicating the spathi Subzone (the dentatus Zone of Sokolov). The inter- 
medins Subzone is also definitely represented including the basal part with Ana- 
hoplites of evolutus type. The next horizon which can definitely be correlated with 
the sequence in the Anglo-Paris basin are Sokolov's zones of ' Anahoplites ' rossicus 
(Sinzov) and ' A. ' uhligi (Semenov). These forms can be matched in the cristatum 
Subzone of Kent, and are descended directly from Anahoplites of the daviesi group, 
which together with its ' variety ' ornata, are also known from this region of the 
U.S.S.R. Spath (1943 ; 732) was quite incorrect in comparing 'A.' uhligi with 
A . daviesi ; the two are quite distinct although closely related. 

Between the Zone of ' Anahoplites ' rossicus and that of A. intermedins Sokolov 
recognises in ascending order a Zone of Daghestanites daghestanensis Glasunova and a 
Zone of Anahoplites kelendensis sp. nov. (of Sokolov which appears to be undescribed) . 
Daghestanites daghestanensis Glasunova has not yet been recognised outside the 
Soviet Union, and Anahoplites kelendensis in the absence of figures cannot be com- 
pared. Undoubtedly the most striking feature of the Middle Albian sequence in this 
area is the apparent total absence of Euhoplites so prolific in the area of Western 
Europe and present also in Greenland. In Siberia the Albian is represented in a 
continental fades. 

The spathi and intermedins Subzones are certainly represented on the northern 
margin of the tethyan belt in northern Bulgaria (Zakharieva-Kovatcheva 1957, 
Nikolov 1965, 1970). Seitz (1930) has figured a definite spathi Subzone fauna on the 
same margin in the Rhaetic Alps at Vorarlberg, Austria. From there westward the 
southern boundary of the province follows the margin through Switzerland and into 
France. The Albian ammonite fauna of the tethyan belt is quite distinct in char- 
acter from that of the European shelf seas and the hoplitinids are absent from Albian 



IN THE ANGLO-PARIS BASIN 133 

sequences south of it. The alleged occurrence of Hoplites (H.) in Mexico has not yet 
been substantiated by illustrations. 

B. Links with the sequences of other countries 

There are two rather fortuitous major links between the hoplitinid faunal province 
and other faunal provinces. The first of these comes in the lyelli Subzone near the 
base of the Middle Albian, the other in the cristatum Subzone at the base of the Upper 
Albian. Between the two there are very few links known. 

(i) WEST PAKISTAN 

Spath (1930b) described an Albian fauna from the area of Hazara, now Abbotabad, 
in W. Pakistan. The ammonites come from a condensed deposit which yielded 
possibly mammillatum Zone, and definitely lyelli Subzone fossils. The lyelli Subzone 
is indicated by the occurrence of Lyelliceras lyelli, L. cotteri, species of Oxytropidoceras 
(sensu lato) and Brancoceras. However, no species of Hoplites (H.) have been re- 
corded. No direct comparison can yet be made with the sequence in the U.S.S.R. 
where this Subzone has not yet been detected, and in fact in the hoplitinid province 
the Subzone is not represented E. of the western area of Switzerland. No other 
Middle Albian links are known from Pakistan, although the cristatum Subzone is 
definitely represented. The two specimens of Oxytropidoceras figured by Spath 
(1934b ; 18-21, 30, pi. vi, figs. 1, 2) from the Attock district are of Middle Albian age, 
but cannot be assigned to a subzone at this time. 

(ii) TETHYAN BELT 

As yet very little knowledge exists on the degree of Zonal and Subzonal repre- 
sentation in the Middle Albian sediments of the part of the tethyan belt stretching 
westwards from W. Pakistan through Iran and Asia Minor, the Mediterranean 
countries to reach the proto-Atlantic on the W. coast of Spain. It is clear that the 
phylloceratids, some lytoceratids, and desmoceratids, where they occur, are too long 
time-ranging to be of even zonal value. Desmoceras latidorsatum, for example, occurs 
in the mammillatum Zone, as well as in the lyelli and intermedius Subzones in the 
Middle Albian hoplitinid province. From the discussion of the American sequences 
it seems that Oxytropidoceras sensu lato may also include long time-ranging species. 
However, the mojsisovicsiinids, and in particular the engonoceratids may eventually 
aid correlation with the provinces to the north and south of Tethys. In this respect 
the distribution of Platiknemiceras is of significance (Casey 1961b). The strati- 
graphic range of this genus as indicated by Casey can in two instances be narrowed. 
It is associated with an example of Lyelliceras gevreyi at Hamiran, Iran (BMNH., 
C 68410) cited by Spath (1931 ; 315) and recorded as Prolyelliceras by Casey (1961b ; 
354). This specimen shows the extra-intercalated siphonal crenules and tendency to 
en-echelon ventro-lateral crenules characteristic of forms which occur at the base of 
the lyelli Subzone. L. flandrini crenulata discussed below is of the same age and is 
also associated with Platyknemiceras. 



134 MIDDLE ALBIAN STRATIGRAPHY 

(iii) ALGERIA 

Although it is in need of revision, the work of Dubourdieu (1953 : 1956 ; 185-228) 
indicates that at least the equivalent of the lower part of the lyelli Subzone is well 
represented by sediments in the Monts du Mellegue, Djebel Ouenza, Djebel Def, the 
environs of the Djebel Hameima, and the Djebel Bou Khadra. The ammonites 
include Lyelliceras flandrini Dubourdieu and L. radenaci (Pervinquiere). L.flandrini 
has extra-intercalated siphonal crenules indicating the lower part of the lyelli Subzone, 
and this is confirmed by L. flandrini crenulata (1953 ; pi. Ill, figs. 25-35) which is 
closely comparable to the inner whorls of the grade reached by L. gevreyi (Jacob) in 
Bed 1 at Courcelles (Aube). L. radenaci occurs also in the lyelli Subzone of the 
Guilford Colliery, Kent (p. 76). 

(iv) SOMALIA 

Tavani (1949) has described and figured what appears to be a lyelliceratid under 
the name Somalites vertebralis. This is associated with Brancoceras and they may 
well indicate the equivalent of the lyelli Subzone. However, Somalites has not been 
found outside its type locality. 

(v) MADAGASCAR 

Collignon has demonstrated recently that the lyelli Subzone is represented without 
question in the Middle Albian sediments of the Malagasy Republic (1963, 1965a) and 
he employs the term Zone a Lyelliceras lyelli. Lyelliceras lyelli and close relatives 
were found by him at Khomihevitra (1963 ; pi. 315, figs. 1333-5). It should also 
be noted that the fauna of brancoceratids described by him (1949) from d'Ambara- 
maninga could well indicate a basal Middle Albian age for the sediments which con- 
tain them. The species of Pseudosonneratia from the same bed certainly do not 
belong to that genus. Dipoloceras cristatum, and contemporary species of this genus, 
marking the unconformable base of the Upper Albian sediments, occur at Andrano- 
fotsy (e.g. Collignon 1963 ; 2). At present it is not possible to correlate the inter- 
vening Middle Albian sediments, referred to a Zone a Oxytropidoceras acutocarinatum 
and Manuaniceras jacobi in the Malagasy Republic, with those of Europe or America. 

(vi) SOUTH AMERICA 

Ammonites of Middle Albian age have been well illustrated from Colombia and in 
particular Peru, and for the purpose of the present comparison these only will be 
considered. Important Middle Albian faunas are also known from other South 
American countries such as Venezuela and Brazil but these have not yet been figured 
in full. 

(a) Colombia 

In Colombia, Gerhardt (1897 ; 168-170, pi. IV, figs. 8a, b) described an ammonite 
which he named Acanthoceras prorsocurvatum from Ubaque (Cundinamarca) and 



IN THE ANGLO-PARIS BASIN 135 

considered it to be of Aptian age. Douville (1906) recognised it to be of Albian age 
and figured a fragment (1906 ; pi. II, figs. 1, ia) which Spath (1930b ; 65 footnote) 
'later renamed Prolyelliceras peruvianum, the type species of his ' genus '. Riedel 
(1934 ; pi. 9, figs. 9-1 1) figured another specimen as Prolyelliceras? lobatum confirm- 
ing a Middle Albian age for these forms, because they are associated with Lyelliceras 
of the lyelli type also figured by him. From specimens in the British Museum (Nat. 
Hist.) e.g. BMNH C 74786 J. V. Harrison Colin., from the road between Viola and 
Portillo, it is apparent that these so-called ' Prolyelliceras ' are in fact large specimens 
of Lyelliceras of lyelli-ulrichi type, the ornament of which modifies at diameters which 
are as yet unknown in the old world. Prolyelliceras is considered here to be a junior 
subjective synonym of Lyelliceras, and the lyelli Subzone is apparently well repre- 
sented in Colombia. 

(b) Peru 

In the last twenty years our knowledge of the Middle Albian zonal stratigraphy of 
Peru has been greatly increased by the work of Knetchel (in Knetchel el al., 1947) 
and Benavides Caceras (1956). It is apparent that the lyelli Subzone is well repre- 
sented in the Pariatambo, Crisnejas and Chulec formations classified by Benavides 
Caceras with the Zone of Oxytropidoceras carbonarium. These sediments, between 
100 and 200 metres thick, have yielded ammonites such as Desmoceras latidorsatum, 
Lyelliceras lyelli, L. ulrichi and Eubrancoceras aegoceratoides , all known from localities 
in the Anglo-Paris basin, especially at Courcelles (Aube). It is interesting to see that 
Benavides-Caceras records Lyelliceras pseudolyelli from Bed 20 of the Crisnejas 
locality classified by him with the underlying Knemiceras raimondii Zone. It is also 
instructive to compare the sequence of Zones recognised in Peru with that of Algeria. 
As yet Mojsisovicsia has not been found in the lyelli Subzone in the Anglo-Paris 
Basin but it does occur in the overlying spathi Subzone where it is represented by 
M. delaruei and subspecies. The genus is represented in Peru by the type species of 
Mojsisovicsia, M. ventallinensis (Gabb) whose exact Subzonal age is uncertain 
(Douglas 1921). It is also uncertain at present whether there are any higher Middle 
Albian sediments than those of the lyelli Subzone preserved in Peru, but it appears 
that the Subzonal sequence is incomplete reflecting the break in sedimentation seen 
elsewhere in the World. 

(vii) TEXAS 

Young (1966) has presented an extremely important work on the ammonite 
zonation of the Fredericksburg Division of the Texas Albian and on the mojsisovic- 
siinid ammonites contained in it. He presents a correlation of the Texas zonal 
sequence with that of Europe. Following a discussion of the faunal sequence both 
in Texas and elsewhere outside the United States, he examines four possible con- 
clusions raised because of an apparent anomaly which exists between the carbon- 
arium Zone of Peru and that of Texas. In Peru the carbonarium Zone of Benavides 
Caceras contains Lyelliceras and it is here correlated with the lyelli Subzone of the 



i 3 6 MIDDLE ALBIAN STRATIGRAPHY 

European Subzonal sequence. In Texas, Young's carbonarium Zone does not con- 
tain Lyelliceras and the possible conclusions that he poses are as follows (1966 ; 18). 

' 1. We do not understand yet the taxonomy and ranges of species of 
Lyelliceras. After all, the entire family Lyelliceratidae is still little known. 

2. The rocks between the dentatus and nitidus subzones are greatly con- 
densed in Peru, Venezuela, and Colombia. 

3. The beds in Texas without diagnostic ammonites (Upper Glen Rose and 
lower Walnut Formations) are to be correlated with the dentatus and benettianus 
subzones, and the zones of salasi and carbonarium are condensed and represent 
all of the Folkestone section between the dentatus and cristatum subzones 
(= beds II-VII, inclusive). " 0. " carbonarium is interpreted with such latitude 
that it could include forms of the salasi zone of Texas. 

4. The ammonite zones are migrating against each other. In other words, 
Lyelliceras is younger in South America than in Europe, and Manuaniceras 
carbonarium is younger in Texas than in South America. This possibility will 
be distasteful to orthochronologists, but it is a factor that cannot be overlooked 
and is supported by the occurrence of Inoceramus concentricus with Lyelliceras 
(Benavides, 1956, p. 414). 

I am inclined to look with favor on the first explanation, but it is a personal 
preference. In the final analyses, some combination of two or more of these 
explanations may seem preferable. I must point out, however, that Benavides' 
(1956) section descriptions do not indicate condensation.' 

Unfortunately it is necessary to point out that the evidence for his correlation of 
the Texas Middle Albian zonal sequence with that of the Anglo-Paris basin is non- 
existent. The only direct correlation that can be made between the two areas is in 
the cristatum Subzone. Dipoloceras fredericksburgense and D. cristatum are known 
from the upper part of the Goodland Limestone in Tarrant Co. Texas. Inoceramus 
subsulcatus was figured by Bose (1927; 189-193, pi. XVIII, figs. 1-5) from the 
Edwards Limestone which is of the same age. But perhaps the most significant 
link is provided by Oxytropidoceras cantianum Spath (1931 ; 350-1, pi. 32, fig. 5) 
which is almost identical to the specimen of ' Manuaniceras carbonarium transitional 
to M. peruvianum multifidum (Steinmann) ', figured by Young (1966 ; pi. 17, fig. 6) 
and which is also from the upper part of the Goodland Limestone (= cristatum Sub- 
zone). The only other possible link is provided by Dipoloceras of the cornutum group 
also known from the Goodland Limestone (e.g. Spath 1931 ; 363 text-fig. 118). 
Now we have the measure of the problem. Oxytropidoceras in the wide sense occurs 
in the Anglo-Paris basin in the mammillatum Zone (Lower Albian), in the lyelli and 
spathi Subzones (Middle Albian), and in the cristatum Subzone (Upper Albian) ; it is, 
therefore, a very long-ranging group. 1 The development of the genus Lyelliceras is 
now well known both in the hoplitinid province and outside it, and the evidence 
indicates that the beds containing it in Pakistan, Madagascar, Algeria, Colombia, 
and Peru are of the same age as those containing Lyelliceras in the Anglo-Paris basin. 
Therefore, the specimens of ' Oxytropidoceras ' carbonarium from the lyelli Subzone 
sediments of the Pariatambo Formation of Peru cannot be of the same age as those 

1 It is now known from the Loricatus Zone of north Kent (Owen in press). 



IN THE ANGLO-PARIS BASIN 137 

occurring in the Goodland Limestone of Texas where they are associated with 
Dipoloceras of the cristatum Subzone. It now becomes apparent that certain species 
of the group typified by Oxytropidoceras, like other tethyan genera, may be very 
long time-ranged. Unlike the hoplitinids which show a great deal of morphological 
differentiation, Oxytropidoceras and its closely allied genera show comparatively 
little such differentiation. On their own, it might prove very difficult, except in a 
few cases, to use them for the fine subdivision of which the hoplitinids have in 
particular proved capable. 

As yet no attempt has been made to compare the species of Oxytropidoceras (s.lat.) 
which are known from the lyelli and spathi Subzones of the Anglo-Paris basin with 
those occurring outside the hoplitinid province. It might well prove possible 
eventually to correlate the spathi Subzone with the tethyan succession (including 
Texas) on the basis of certain species of Oxytropidoceras (s.lat.). At the moment the 
intermedins and niobe Subzones have no exact zonal links with Tethys although long 
ranged tethyan forms are known from both time spans. Mojsisovicsia in the sub- 
delaruei Subzone should be a renewed tethyan incursion, but none of the species from 
this Subzone or the lautus Zone have yet been recognised elsewhere. So, at this time 
it is not possible to correlate the Zones recognised in Texas with those of the Anglo- 
Paris basin. It is however, apparent from Texas and Madagascar that sediments 
characterised by the group typified by Oxytropidoceras occur between the lyelli and 
cristatum Subzones. Although sedimentary breaks can be difficult to detect in 
carbonate-marl sequences it seems to the writer that Young's salasi and carbonarium 
Zones are high Middle Albian as he states. 

(viii) CANADA 

The zonal scheme of the Canadian Albian has recently been ably reviewed by 
Jeletzky (1968), but although this represents a refinement on his earlier review of 
1964 it is still open to criticism. In 1964 Jeletzky indicated that the Zone of 
Arcthoplites mcconnelli contained Cleoniceras and Cymahoplites. If these ammonites 
are correctly assigned generically then together they indicate a Lower Albian, mam- 
millatum Zone age in the sense of Casey (1961a ; Table 1) and herein. Cymahoplites 
occurs in the mammillatum Zone of Europe (Casey 1961c ; 165-169, PL XXIX, figs, 
ia-d), and although Cleoniceras (C.) ranges from the tardefurcata Zone (regularis 
Subzone) to the basal Middle Albian eodentatus Subzone, the weight of evidence, from 
the associated ammonites indicates a mammillatum Zone age. There is no evidence 
at this time to indicate that the Subzones of Lemur ocer as irenense and L. mcconnelli 
are the correlatives of the European Subzone of Douvilleiceras inaequinodum (Jeletzky 
1968 ; Fig. 1) now the basal Middle Albian Subzone oiHoplites (Isohoplites) eodentatus. 

The Gastroplites Zone has been equated by Jeletzky (1968 ; Fig. 1) with both the 
daviesi Subzone (Middle Albian) and the cristatum Subzone (Upper Albian). How- 
ever, G. cantianus Spath which occurs in the Gastroplites Zone in Canada occurs also 
in Bed VIII at Folkestone its type locality. It is undoubtedly of cristatum Subzone 
age, and there is no evidence for correlating the daviesi Subzone with any part of the 
Gastroplites Zone at this time. 



13S MIDDLE ALBIAN STRATIGRAPHY 

Between the Gastroplites Zone marking the base of the Upper Albian and the 
mcconnelli Subzone is a thick interval of shales which have not yet yielded ammonites. 
Jeletzky has classified these sediments with a Zone F which he considers to include 
part or all of the time span between the mammillatum ' Subzone ' and the cristatum 
Subzone (1968 ; 17-18, Fig. 1). If there are any Middle Albian sediments in Canada 
then they are contained in these shales of Zone F. At the moment, however, no 
Middle Albian ammonites are known from Canada. It is worth noting that the 
alleged Cleoniceras associated with a gastroplitinid ammonite fauna in Alaska (Imlay 
1961) does not stand up after examination. Cleoniceras (Grycia) sublet Imlay which 
is known from crushed material does not appear to possess umbilical bullae and is 
here considered to be a member of Beudanticeratinae. The gastroplitinid Upper 
Albian province included the area that is now the western cordillera of North 
America stretching from Alaska to California. 



(ix) GREENLAND 

Our knowledge of the Albian sediments of the area between Traill 0. and the 
Wollaston Foreland on the E. coast of Greenland N. of Scoresby Sound, is due to the 
work of Spath (e.g. 1946 ; 8-10) and Donovan (1949 ; 6-7 : 1953, 35-37, 50-51). It 
is tantalising in its incompleteness for it seems that in this area we have the boundary 
between the European Albian province and that of the area of Canada and the western 
cordillera of N. America. Both Spath and Donovan record Lower Albian ammonites 
which occur in both provinces ; Middle Albian ammonites such as Hoplites and 
Euhoplites which are characteristic of the European hoplitinid province ; and Upper 
Albian ammonites which may also link the two provinces. 



(x) CONCLUSION 

The foregoing very brief review indicates that a considerable amount of work now 
requires to be done on Middle Albian sequences outside the Anglo-Paris Basin along 
the lines attempted here. The object of this review is to stimulate such research. 
Superficially, it seems that there is in many parts of the Earth a major break in 
sedimentation, particularly at the top of the Middle Albian. General sedimentation 
occurred once again in early Upper Albian times. There is evidence of this even in 
the area of Kent and Sussex, wherein the loricatus and lautus Zones are apparently 
the most completely represented by sediments. Breaks of such an extensive nature 
in the Cretaceous, must be due to major events in the Earth's crustal development, 
for there is no evidence of unusual climatic conditions of sufficient magnitude to 
reduce sea-level by a significant amount. 

There has always been a tendency to equate movements on a regional scale in 
Europe with various periods of deformation in the Tethyan belt. Until recently the 
development of the Atlantic, Arctic and Pacific ocean basins has been largely ignored 
and yet with recent geophysical work we are now beginning to see the important 
effect that initial faulting must have had even on Cretaceous sedimentation. The 



IN THE ANGLO-PARIS BASIN 139 

Royal Society's Symposium on Continental Drift posed many new questions for the 
stratigrapher and challenged many long held concepts. The important reviews by 
Wilson (1965 ; 228-251), and Maack (1969) on the formation of the ocean basins drew 
particular attention to the role and effect of initial major rift, block and transcurrent 
faulting in the Jurassic and Cretaceous before the pulling apart of the old continents 
to the positions of the new within the Tertiary. The evidence of faulting and igneous 
activity indicate that the pulling apart of the continental masses bordering the 
present day Atlantic commenced earlier in the southern Atlantic (e.g. Maack 1969). 
In the northern Atlantic the vulcanism commenced in the Tertiary. 

The major faulting must at times have had a profound effect on the distribution 
and depth of water, and thus the depositional and erosional conditions, in the 
continental shelf seas. This would produce characteristics quite distinct from the 
pressure of the African continent against Europe which in the Tertiary culminated 
in the Alpine ' storm '. During the Albian there is good evidence of the effect of 
this faulting, associated with the separation of Africa and South America, in and 
around Africa (e.g. Furon 1963). Even in southern England faulting occurred 
during cristatum Subzone times associated with marked erosion of Middle Albian 
sediments. This is but one symptom of one short period of crustal instability which 
is apparent in both the sediments and fauna in a number of areas in the World and 
points to a significant event in the development of the Earth. 

The old idea of a Jurassic and Cretaceous North Atlantis continent now foundered 
below the N. Atlantic was not so far off the mark. However, this ancient land mass 
was the continental area which is now Greenland and Canada, long before it was 
broken up and pulled away from Europe since the Tertiary to the present day. It is 
apparent that the boundary between the Albian ammonite provinces of the deposi- 
tional areas that is now Europe, and that of Canada and the Western Cordillera of N. 
America, occurred in the sea-way represented by the sediments in E. Greenland. 

VI. CONDITIONS OF DEPOSITION IN ENGLAND 

From the stratigraphical account of the Middle Albian sediments given above it is 
possible to obtain some idea of the conditions which influenced their deposition in 
England. Before commencing the discussion of these it is essential to consider first 
two factors which provide a key to the interpretation of the field evidence. 

It is apparent that the early Upper Albian {cristatum and orbignyi Subzones) 
tectonic movements caused the planing-off of the upper surface of the Middle Albian 
sediments throughout England. This period of erosion, although not as great as 
Kitchin & Pringle held (1922a), removed a considerable amount of sediment, 
including marginal deposits. Within a reasonably narrow limit the resulting surface 
was probably plane, and for the purpose of this study it is taken so to be. From this 
datum level, by comparing both the surviving thickness and the lithological sequence 
from place to place, it is possible to make out the configuration of the surface upon 
which the Middle Albian sediments were deposited. 

It appears that there were only comparatively minor regional tectonic movements 
within Middle Albian times. These seem to have consisted of minor shifting of the 
axes of older folds indicated below, causing condensation or increased sedimentation. 



14>> MIDDLE ALBIAN STRATIGRAPHY 

The main factor governing sedimentation appears to have been the pattern of 
parallel ridges and troughs produced initially in late tardefurcata Zone times by a 
comparatively mild folding phase. Casey from the field evidence afforded by largely 
remanie mammillatum Zone deposits interpreted these troughs as ' dimples ' (1961a), 
but the Middle Albian sediments have provided far more definite information on the 
trend of these structures (text-fig. 52). 

Although the ridges were not obviously active structures the sediments thin across 
them due to water-current activity, and probably to some gravitational movement 
of clay particles down-slope. During minor periods of current erosion the degree of 
condensation is greater in the area of the ridges as one would expect. 

(a) The Margins of the depositional basin 
in England and Northern France (text-fig. 51) 

To what extent the Brabant massif and the London Platform acted as positive 
areas in Middle Albian times is far from certain. Nothing is yet known of the Gault 
sequence in the area of the North Sea adjacent to the shores of Kent, Essex, Suffolk 
and Norfolk. There certainly is no evidence made available at this time of the land 
area suggested in this region by Jukes-Browne's frontispiece map (1900). It is also 
apparent from the borings in the Cliff e area of Kent (Owen in press), that renewed 
movements along late Jurassic or early Cretaceous faults in the area of what is now 
the Thames estuary, caused strong current action which removed Middle Albian 
sediments over the southern part of Essex. This disturbance contributed to, and 
was associated with other movements which planed-off the upper surface of the Lower 
Gault throughout the Anglo-Paris Basin. How much sediment and the areal extent 
that has been removed is at present unknown, but in Kent, and in Cambridgeshire 
and Norfolk, where Middle Albian sediments are preserved, there is no evidence in 
the sequence of an area of Palaeozoic rocks actively undergoing erosion to the east. 

A shoal area existed in north-west Norfolk and in the area of the Lincolnshire and 
Yorkshire Wolds and to an unknown extent in the adjacent area of the North Sea. 
Its position is indicated by the pebbly development of Bed C of the Hunstanton Red 
Rock (Wiltshire 1869 ; 185-188) of Middle Albian age, and its lateral equivalents 
in the Red Chalk with its shallow-water fauna. To the south and east in Norfolk, 
Bed C is replaced by clays of the contiguous Lower Gault. This shoal area probably 
flanked the Palaeozoic massif of the Pennines and its southerly extension of the Peak 
District and a possible positive area in the adjacent North Sea (Collette 1968 ; 20). 
Gault clay probably existed south of the Pennine massif because derived Albian 
fossils are known from the glacial boulder clay as far north as Chellaston, Derbyshire, 
as well as elsewhere in the Midlands. 

On the balance of evidence the writer is inclined to doubt that the Middle Albian 
sea extended into the Cheshire lowlands but this could prove to be incorrect. The 
clays of the lyelli and spathi Subzones at Swindon (Badbury Wick) and at Devizes are 
very silty. Those of the intermedins Subzone at Devizes and Didcot are even coarser 
in grade. These examples do not necessarily indicate the proximity of a marginal 
area but equally they do not suggest an extensive basin area to the north west. 



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Fig. 51. Palaeogeographic map of the Anglo-Paris Basin in the Middle Albian showing 
links with the North Sea Basin, and Tethys via the Morvano-Vosges Strait. The 
Aquitaine Basin is linked with Tethys via the proto-Atlantic. 



i,j MIDDLE ALBIAN STRATIGRAPHY 

Nonetheless, the outcrop from Aylesbury (Bucks.) to Okeford Fitzpaine (Dorset) 
shows a section across a basin in which the lyelli Subzone in particular is well devel- 
oped, and apparently the intermedins Subzone as well. Whether the margin of the 
Middle Albian depositional area ever reached Palaeozoic rocks in the Welsh 
borders is unknown. However, it seems more probable that the margin flanked a 
land area of Jurassic rocks from the nature of the sediments of the Gault in this area 
(compare the relationship seen in the Ardennes). There is no doubt that a con- 
siderable volume of clay sediment was carried eastwards into the depositional area 
throughout Middle Albian times (p. 147) (cf. Jones 1955). 

It has been shown (p. 53) that as one proceeds westwards along the south coast 
from the Isle of Wight to the Devon border the basal fossiliferous bed and presumably 
the underlying pebble beds become later in age. In the deeper part of the Wessex 
Basin in the Isle of Wight, fine grade lyelli Subzone sediments rest upon coarsely- 
graded marginal mammillatum Zone Carstone. By Lyme Regis, the lowest fossili- 
ferous sediments are of intermedins Subzone age consisting of very gritty clays, and 
rest upon a pebble bed which is of uncertain Subzonal age but probably not older than 
spathi. The evidence indicates marked diachronism of the base of the Middle 
Albian sediments, and the progressive transgression of the sea westwards across 
Jurassic sediments particularly during the spathi Subzone. The furthest margin in 
the extreme west probably followed the eastern boundary of the Mendip Hills and 
across to the area of what is now the Blackdown Hills. There is no evidence of any 
Middle Albian sediments in the western half of the English Channel. 

On the northern coast of France, Middle Albian marginal sediments probably 
flanked the Palaeozoic rocks north of the Cotentin Peninsula. They are certainly 
present in the Pays de Caux where sediments of the eodentatus and niobe Subzones 
consist of very coarse pebbly loams with a high clay content. However, the available 
evidence from the outcrop and boreholes indicates that the land margin was not to 
the south-west, south, or south-east, and it is necessary to look for a ridge which 
underwent active erosion during the Middle Albian in the Baie de la Seine. There 
seems no doubt that the western margin of the Middle Albian Paris Basin was flanked 
by Jurassic sediments fringing the Armoricain Massif (text-fig. 33). 

In the Artois, the eastern margin of the Middle Albian sea was formed by the 
Brabant Massif. In the Boulonnais at Cafflers, and in borings in the area of the 
Franco-Belgian border, Albian sediments rest upon Palaeozoic rocks on the fringe 
of the Massif. Of particular interest here, especially in connection with the thinning 
of Middle Albian sediments in the extreme east of Kent, is the marked rise in the 
Palaeozoic floor in the region of the Ouenoc off-shore from Cap Blanc Nez (p. 83). 

In general, therefore, it is apparent that in England and in France a progressive 
transgression over earlier Cretaceous and on to wide areas of Jurassic sediments 
occurred between the eodentatus and niobe Subzones. Whether this continued later 
into the loricatus and lautus Zones is uncertain because early Upper Albian erosion has 
removed the evidence. From this definition of the margin of the northern part of 
the Anglo-Paris Basin, it is now possible to look at the structures within the de- 
positional area in England. 



IN THE ANGLO-PARIS BASIN 143 

(b) The Structural Controls on Deposition 
in southern England (text-fig. 52) 

The Variscan Wessex Basin of Kent (1949 ; 99) and its continuations into the 
Weald and across the Channel into France subsided fairly steadily throughout the 
Jurassic roughly in pace with the sediments which infilled it. At the end of the 
Jurassic and at the opening of the Cretaceous Period, a strong phase of folding 
and faulting occurred which in Dorset must have included fold amplitudes of well 
over 1000 feet (>305 m.). The resulting basin of sedimentation was very greatly 
reduced in area in comparison with that of the Jurassic. The history of Lower 
Cretaceous sedimentation in southern England is the progressive erosion of the 
resulting land area of Jurassic sediments and their redeposition within the basin. 
This basin was by now restricted to the area of the Weald proper and eastern Hamp- 
shire, and the English Channel flanking the Isle of Wight and Sussex. That the 
deformation was essentially early Cretaceous is indicated by the distribution and 
character of the Purbeck Beds and contiguous deposits. The marine Cinder Bed 
within the Purbeck Beds of Dorset and equivalent horizons elsewhere are considered 
by Casey to mark a marine incursion from the direction of the North Sea Basin (1963). 
The sea did not invade southern England again until the early Aptian. It is 
also important to note that in the Speeton area it is the top of the Kimmeridge 
Clay which is eroded and that heavy clay sedimentation did not commence again 
until after the start of the Neocomian. 

The depositional history of the Lower Greensand has been discussed by Casey 
(1961a ; 499-501). At the end of the tardefurcata Zone (Lower Albian) there occurred 
the last of a number of minor folding phases which Casey has demonstrated affected 
sedimentation during the formation of the Lower Greensand. This last phase 
produced a number of parallel ridges and troughs trending between NW. and SE. to 
WNW.-ESE. , the axes of which were slightly modified during mammillatum Zone times 
and again later in loricatus Zone times. These, together with a general subsidence 
of the whole Basin both in England and France or a rise in sea-level, set the stage for 
Middle Albian sedimentation. The positions of the axes of the structures are shown 
diagrammatically in text-fig. 52. 

The Middle Albian sequence under Dover shows a good development of the lyelli 
Subzone overlain by a nodule bed of lower spathi Subzone age. By Folkestone the 
lyelli Subzone sediments are greatly reduced in thickness but the overlying dentatus 
nodule bed is of exactly the same age as at Dover. The rest of the Lower Gault 
sequence also is thinner at Folkestone, where it rests upon a mammillatum Zone 
sequence in which all four Subzones are represented. 

At Sandling Junction, the basal Gault rests upon puzosianus Subzone sediments as 
at Folkestone, but these in turn rest directly on an eroded surface of early tardefurcata 
Zone sediments. Here, the dentatus nodule bed contains species of Hoplites (H.) 
transitional between those of the dentatus nodule bed at Folkestone and Dover, and 
those which occur in the ' upper dentatus-spathi nodule bed ' in the northern Weald. 
From Sandling to Maidstone, puzosianus Subzone sediments rest upon either tarde- 
furcata or jacobi Zone Folkestone Beds, and the dentatus nodule bed in the basal Gault 



M4 



MIDDLE ALBIAN STRATIGRAPHY 




T3 
V 
W 

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bo 

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bo 

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T3 

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IN THE ANGLO-PARIS BASIN 145 

has exactly the same degree of representation as at Sandling. There is strong 
evidence to indicate that in lithological sequence and Subzonal representation the 
remainder of the Gault sequence is uniform between Brabourne and the A 249 Clover 
Leaf on the Maidstone By-Pass, and they are certainly identical from Hollingbourne 
to the A 249. 

In the area of the Kent Coalfield to the east, the pattern is not so clear but the 
eodentatus and lyelli Subzones sediments are well developed to the N. and NW. of 
Dover in the Guilford, Tilmanstone, and Chislet collieries. The Lower Gault as a 
whole is much thicker here than at the outcrop, but further east, on the Thanet and 
E. Kent coast, the Gault in its entirety thins rapidly. 

At the valley of the Medway north of Maidstone, the outcrop swings westwards 
through an arc of about 12 °. The change in the lithological sequence is striking 
(text-fig. 3, p. 14) as the outcrop turns away from the line parallel to an axes to one 
that cuts across the structural trend. From the four-division sequence in the Maid- 
stone By-Pass, the Lower Gault expands into the six-division sequence recognisable 
from Paddleworth near Snodland westwards at least as far as Dunton Green. The 
central area of this Middle Albian trough seen in section at the outcrop occurs 
roughly in the position of the Sevenoaks Brick Works but it migrated slightly NE. 
during Middle Albian times. At Sevenoaks, the top of the Folkestone Beds contain 
developments of soft sandstone in regular beds. This is overlain by a comparatively 
thick development of the mammillatum Zone sediments. The top of lyelli Subzone 
and the lower part of the spathi Subzone are represented by fine clays in contrast to 
glauconitic clays or loam at Ford Place on the one side and at Dunton Green on the 
other. The overlying ' upper dentatus-spathi nodule bed ' contains an ammonite 
assemblage identical to that seen in all sections from Parsons Corner, Snodland, 
to the Shere By-Pass. The remainder of the Lower Gault Divisions at Seven- 
oaks when compared with Ford Place show the offset of the trough axes towards 
the NE. 

The whole Middle Albian sequence thins from the Sevenoaks Brick Works towards 
Dunton Green. Further west, the eodentatus, lyelli, and spathi Subzones at least, 
expand and are well developed in the area between Brasted and Covers Farm west 
of Westerham. Unfortunately the rest of the Lower Gault is not exposed although 
from the Brasted well it also is expanding west of Dunton Green. This boring also 
demonstrates that the mammillatum Zone troughs do not always correspond to those 
of the Middle Albian sediments, for here the mammillatum Zone sediments are much 
thicker than those to the east and west and are little condensed. In the Addington 
Pumping Station situated 9! miles WNW. of Dunton Green the Lower Gault is of 
much the same thickness and probably lies near a common ridge axis, running NW. 
from Dunton Green. 

At the Buckland Sand & Silica Co's pit together with Wray Common, at Reigate, 
the sequence although in general thicker and the sediments coarser, shows a similar 
succession to that seen at Ford Place. At Shere, however, the eodentatus, lyelli and 
basal spathi Subzones are again relatively well developed, but from here westwards 
to Farnham the information is either poor or of uncertain value. Moreover, the 
outcrop is faulted over much of this stretch of country. 

K 



r 4 6 MIDDLE ALBIAN STRATIGRAPHY 

From the foregoing brief description, the evidence for NW. to SE. trending ridges 
and troughs is not conclusive, but is very strong. However, in the southern Weald 
and the Isle of Wight three pieces of evidence, in the writer's opinion, tip the balance 
strongly in favour of the interpretation here given. 

The spathi Subzone sequence expands southwards from Wrecclesham to reach 
a known maximum thickness at Selborne. From there it thins southwards towards 
Nyewood, but the lithological sequence in detail remains the same. Although there 
is a partial facies change and the sediments are coarser in E. Hampshire and W. 
Sussex, the sequence in the spathi Subzone at Selborne lithologically is remarkably 
close to that of the Horton Clay Pit, Upper Beeding (text-fig. 14, opp. p. 42) where it is 
underlain by a thick development of the lyelli Subzone. Yet this sequence at Horton 
Hall is quite different to that seen at Storrington where the lyelli Subzone sediments 
have not been proved and if present at all are very thin and pebbly. In the opposite 
direction, at Hassocks, the eodentatus and lyelli Subzones sediments are still well 
developed but are grittier and more glauconitic and here as at Storrington the Gault 
rests upon an ' Iron-grit ' which forms the indurated top of the sands of the Folkestone 
Beds. At Horton Hall, however, the tardefurcata Zone is represented within clays 
and loams, totally different to that of Hassocks and Storrington. 

Along the WNW.-ESE. trending outcrop at the base of the South Downs from 
Storrington to Petersfield, the Gault rests upon the ' Iron-grit ' (Kirkaldy 1935), below 
which are normal loose sands of the Folkestone Beds. This sequence is seen at 
Portsdown where the pre-Gault Lower Cretaceous sediments are greatly attenuated. 
This area in which the ' Iron-grit ' is present at the base of the Gault marks a long 
swell on the pre-Middle Albian sea-floor which apparently increased in amplitude 
towards the ESE. (p. 34). The sequence on the other side of the trough at Hassocks 
has already been mentioned, and from what little is known of the Lower Albian 
sequence near Eastbourne, and the Middle Albian sequence at Ringmer, the trough 
extended ESE. from Upper Beeding towards Eastbourne. The sedimentation 
remains very thick along this axis and if one projects the line through Selborne 
into Wiltshire it again coincides with a broader area of thick dentatus Zone 
sedimentation. 

On the other, southern, side of the Storrington-Portsdown swell the lithological 
sequence in the eodentatus, lyelli, and spathi Subzones in the Isle of Wight is totally 
different from that of the Ringmer-Selborne trough. It is possible therefore, that 
yet another WNW.-ESE. trending trough exists in the English Channel and which 
includes the Isle of Wight. Both the mammillatum Zone sequence and the Lower 
Gault increase in degree of representation towards the southern part of the Island. 
The diachronous base of the Gault along the Dorset Coast can be explained if one 
considers this line to be a diagonal section across the trough, the intermedins Sub- 
zone sediments in the Charmouth area being near the southern bounding ridge which 
may have flanked a positive area in view of the sequence in the Pays de Caux. 

In the E. and NE. part of the Weald the axes of the parallel ridges and troughs 
trend as far as it is possible to judge in a NW. to SE. direction and they are with the 
possible exception of the Kent Coalfield fairly closely set and linear (text-fig. 52). 
The apparent opening-out of the troughs in the northern Weald W. of Dunton Green 



IN THE ANGLO-PARIS BASIN 147 

is due partly to the fact that the outcrop tends to swing more parallel to the axes. 
In the southern Weald the axes have swung WNW.-ESE. and the structures are 
more open. These structures have what is normaUy considered to be an Armorican 
trend, and the Middle Albian is the last time that such closely lineated structures are 
fully identifiable in the depositional environment. 

(c) Source of the Middle Albian Sediments 

Middle Albian sediments ranging in age from the eodentatus Subzone to the 
intermedins Subzone rest, outside the area of the Weald and the eastern part of 
Hampshire, the Isle of Wight and part of Purbeck, and the area extending NE. of 
Aylesbury, directly upon Jurassic rocks. These Jurassic rocks had been folded and 
faulted in the late Jurassic-early Cretaceous to become land. Below the London area 
andN. Kent the Lower Gault, when present, rests upon thin Lower Greensand which 
is underlain by either Jurassic or Palaeozoic rocks. The Middle Albian sea, therefore, 
was clearly transgressive far outstripping the depositional area of the Lower Green- 
sand which itself oversteps the Wealden and both of which derived their sediments 
from the Jurassic land area. It is evident from the cobbles and blocks included 
in the mammillatum Zone sediments of Kent that Palaeozoic rocks of the London 
Platform were by then undergoing active erosion. From the borings in N. and 
E. Kent there is no evidence, however, that the London Platform contributed 
any large quantity of sediment during the deposition of the Lower Gault. This 
probably consisted only of the silty fraction which is mixed with a fine clay 
fraction. 

In general as one moves west from the Kent coast the Middle Albian clays coarsen 
in particle size and increase in the quantity of admixed silt and sand. This is readily 
apparent if one compares for example in succession the sediments of the intermedius 
Subzones at Folkestone, Buckland, in the Winchester borings, Devizes, and on the 
Dorset coast in the Charmouth area. This suggests a main sediment source from 
the western and north western margins of the sea, and possibly also from the south 
in the area of the English Channel. 

On the coast in the Isle of Purbeck and towards Weymouth and in the Charmouth 
area the diachronous base of the Gault can be seen to rest directly upon extensive areas 
of Jurassic clays such as the Kimmeridge Clay, Oxford Clay, and the Lias (text-fig. 
23). In the area of the Hampshire Basin, British Petroleum Co., borings at Bere 
Regis near Wareham (Dorset) and at Fordingbridge (Hants) show the Gault to rest 
directly upon Oxford Clay and Kimmeridge Clay respectively. Along the northern out- 
crop the position is much the same (text-fig. 18), with Middle Albian sediments resting 
upon the Lias in the far west and then eastwards upon an eroded surface of folded 
Jurassic sediments in which the Oxford and Kimmeridge Clays bulk large. Now this 
is the state of affairs within the area of the depositional basin itself already having 
undergone erosion since early Cretaceous times. Moreover, this is the depositional 
basin which extended rapidly during spathi Subzone times to its greatest known 
Middle Albian extent in the intermedius Subzone. Without any question the 
originally far greater depositional area of the Jurassic clays must have undergone 

K* 



148 MIDDLE ALBIAN STRATIGRAPHY 

active erosion during this period, and the Middle Albian sea may well have extended 
further during later Subzones. In the writer's opinion all the evidence points to a 
source in the clays of the Jurassic, west of the London Platform, for the sediment 
which was redeposited as the Lower Gault. 

A Jurassic source to the west in Wales is suggested by the work of Jones (1955 ; 
348-50), and by the borings at Port More, Antrim (Robbie & Manning 1966), and 
Mochras, Merioneth (Wood & Woodland 1969) in which Lias is preserved. At 
Port More, the incomplete remnant of Lower Lias is overlain by Upper Chalk 
indicating a major intra-Mesozoic hiatus, the exact nature and extent of which is 
uncertain at present. 

Much the same state of affairs existed in the Paris Basin and it is an interesting 
fact that here also the Middle Albian sediments are coarser in the west and finer in 
the eastern areas of the Basin. 

(d) The cristatum Subzone disturbance 

After the commencement of the cristatum Subzone, a major disturbance affected 
the whole of the Anglo-Paris Basin and adj oining areas. In fact a break in sedimenta- 
tion associated with erosion occurs widely throughout the Earth at about this time, 
and is sometimes accompanied by folding. The disturbance caused the partial 
planing-off of Middle Albian sediments over the whole area of the Anglo-Paris Basin . 

The writer considered (i960 ; 377) that the planing-off of the upper surface of the 
Lower Gault in southern England was due to a tilting movement up towards the west. 
This may be true for the eastern half of England where definite early Upper Albian 
faulting has been proved (Owen in press), but it is not necessarily the explanation 
for the southern part of the country as a whole. In France, there is some evidence 
of a similar tilting movement towards Morvan and Armorica. Although the effects 
on the sediments is readily apparent, the main cause is much more obscure and may 
be connected with faulting at the margin of Europe and America before the later de- 
velopment of the Atlantic Ocean (p. 138). 

Tectonic features are few in number, and there is certainly no evidence of anything 
but a slight broad warping of the Basin as a whole, except for the faulting mentioned 
above which removed Lower Gault sediments at least from the southern part of 
Essex. The turbulent water conditions are reflected in the nektonic fauna ; for 
example Inoceramus concentricus quite rapidly develops the far stronger sulcatus 
form, and does not revert back to a concentricus form until the varicosum Subzone 
when thick, little condensed sequences are seen again. 

On the resulting planed-off Middle Albian surface Upper Albian sediments were 
laid down in an entirely different pattern to that seen in the Middle Albian. More- 
over, there are two intergrading facies ; the Upper Greensand and the Upper Gault. 
This change in pattern renders meaningless isopachyte maps based on the sediments 
of the whole Stage (Wooldridge & Linton 1938). It appears at present that the 
Upper Albian depositional pattern is more closely related to that of the Upper 
Cretaceous. 



IN THE ANGLO-PARIS BASIN 149 

VII. REVIEW OF THE AMMONITE FAUNA 

The foregoing stratigraphical account has drawn heavily upon the evidence of 
relative ages provided by the ammonites. For the purpose of this Bulletin the 
subzonal distribution of the ammonite fauna of the Middle Albian, will be considered 
only. Of the other stratigraphically useful fossils, some have been mentioned in the 
text, but the foraminifera and ostracods require careful revision based on accurate 
collecting. The two plates of zonal ammonites should be used in conjunction with 
Spath's Monograph (1923-43). 



A. Description of new species 

In order to stabilize the new taxa used in this Bulletin, brief descriptions are given 
of one species of Hoplites (H.) and two species of Anahoplites. 

Family HOPLITIDAE Douville 1890 
Subfamily HOPLITINAE Douville 1890 
Genus HOPLITES Neumayr 1875 
Subgenus HOPLITES Neumayr 1875 

Hoplites (Hoplites) maritimus sp. nov. 

(PI. 1, figs. 3 a, b) 

1925a Hoplites rudis Parona & Bonarelli (pars) ; Spath : 108, pi. 8, fig. 10c, d. 

Derivation of name. Hoplites : — heavily armoured soldier, maritimus : — of the 
sea. 

Diagnosis. Hoplites {Hoplites) with stout well-rounded whorl section bearing 
coarse projecting tuberculate bullae about 10 per whorl, each buttressed by short 
umbilical rib stemming from umbilical suture. Each bulla gives rise to two short 
coarse ribs terminating above ventrolateral margin in coarse projecting clavi arranged 
en-echelon each side of venter : intercostal areas merging onto venter. Ribs simple to 
about 40 mm. diameter, thereafter there is tendency to develop occasional lautiform 
ribs. Above 100 mm. ornament decreases in strength. Septal suture similar to 
H. (H.) dentatus. 

Type material. Holotype BMNH. C 862a (J. S. Gardner Coll.) from Bed I (v) at 
Folkestone. 

Dimensions. 53 -42 '$2 -32. 

Remarks. Like all species of this genus, H. (H.) maritimus shows variation 
among individuals. Specimens of this form are, however, common in the lower part 
of the spathi Subzone taking descent from the lyelli Subzone H. (H.) of the baylei- 
benettianus group. At the base of the Subzone the ribbing is usually simple, but 
higher up occasional intercalated ribs occur which produce a lautiform effect. Later 
still, lautiform ribbing becomes well developed producing direct transitions to H. (H.) 
canavarii Parona & Bonarelli of the upper part of the spathi Subzone. 



i 5 o MIDDLE ALBIAN STRATIGRAPHY 

When found in condensed phosphatic nodule beds, this species shows a bewildering 
series of morphological transitions to other coarsely ornamented species of Hoplites. 
Most of these transitions are more apparent than real, in that coarse members of a 
number of indirectly related offshoots which developed at slightly different times 
have been collected together en melee in the same bed. To Spath it appeared that 
this species belonged to Parona & Bonarelli's Hoplites rudis but was not typical of it 
(1925a ; 108). H. (H.) rudis does occur in England in the upper dentatus-spathi 
nodule bed in the northern Weald, however, in the writer's opinion it represents a 
coarse end member of a different development of Hoplites {H.). 

Horizon & localities. The species occurs throughout the spathi Subzone and is 
ubiquitous in the Anglo-Paris basin. 



Genus ANAHOPLITES Hyatt 1900 

Anahoplites osmingtonensis sp. nov. 

(PI. 1, figs, ia, b) 

1925a Anahoplites mimeticus Spath (pars) ; Spath : 142. 

1927 Anahoplites mimeticus Spath (pars) ; Spath : 188, pi. 17, figs. 8a, b. 

Derivation of name. From Osmington, Dorset, the type locality. 

Diagnosis. Anahoplites of the intermedins group : discoidal, compressed, evolute, 
with excentric umbilicus. Umbilical wall steep in early whorls becoming rounded in 
outer whorl. Umbilical margin marked by faint comma-shaped bullae giving rise to 
faint striate ribs on gently curving whorl flank, terminating on ventro-lateral shoulders 
at faint clavi absent on body chamber. Venter subtabulate slightly sulcate. 
Suture line like A . planus, but symmetrical across venter and highly interlocked. 

Type material. Holotype BMNH., C 68385 (T. F. Grimsdale Coll.). Uppermost 
spathi Subzone between Osmington Mills and Black Head, Dorset. Paratypes 
BMNH., C 26595 same collection, horizon, and locality as Holotype. BMNH., 
37604 (Astier Coll.) condensed Middle Albian phosphatic bed, Escragnolles, Alpes 
Maritimes, France. 



•33 (Holotype is slightly crushed) 
•30 

Remarks. This species differs from Anahoplites planus (Mantell) in its marked 
excentric umbilicus, slightly sulcate venter which becomes broadly rounded on the 
body chamber, and the symmetrical arrangement of the suture line each side of the 
venter. The elements of the suture line are closely interlocked resembling specimens 
of A. planus from the cristatum Subzone. It is, however, probably not directly 
related to A. planus, an early mutation of which occurs in the same bed (e.g. Spath 
1927 ; 188, pi. 18, figs. 7a, b), but is very near the stem from which A. grimsdalei, 
A . evolutus, A . intermedins, A . mantelli, A . praecox, and A . alternatus sprang. 



Dimensions. 








C 68385 


[107] 


•39 


•25 


37604 


107 


•40 


•28 



IN THE ANGLO-PARIS BASIN 151 

Spath referred the paratypes of A. osmingtonensis to A. mimetictis. However, 
the type of A. mimeticus (BMNH. C 30535, 1925 ; 131, pi. 11, figs. 7a, b) shows that 
the inner whorls are strongly costate with well developed umbilical bullae quite 
unlike A. osmingtonensis and in fact probably does not belong to Anahoplites at all. 
The stratigraphical horizon of the Holotype of A. mimeticus has been discussed 
above (p. 47), and it is not considered here to belong to the mammillatum Zone genus 
Anahoplitoides (Casey 1966 ; 547-8). 

Horizon & localities. A. osmingtonensis occurs at the extreme top of the spathi 
Subzone both in the Osmington area of Dorset, and the Petersfield area, Hampshire 
(BMNH. C 35483). It is also present in the condensed spathi, intermedins Subzones 
assemblage of Bed 4 at the Carriere Binot, St. Florentin (Yonne), and also at 
Escragnolles (Alpes Maritimes) . 



Anahoplites grimsdalei sp. nov. 
(PI. 1, figs. 2a, b) 

Derivation of name. After Mr. T. F. Grimsdale. 

Diagnosis. Anahoplites of the intermedins group ; discoidal, compressed, evolute. 
Umbilical wall rounded, marked at margin by 20 comma-shaped bullae on outer 
complete whorl. Each bulla gives rise to primary rib which bifurcates either just 
above it or near middle of whorl flank. Ribs sickle-shaped, faint on inner whorls 
terminating at ventro-lateral margins in distinct clavi arranged en-echelon each side of 
tabulate slightly sulcate venter. Occasional short intercalated ribs stem from 
primary ribs, one for each primary, on ventro-lateral shoulder to end at ventro- 
lateral margin in intercalated clavi. Suture fine as in A . intermedins. 

Type material. Holotype BMNH. C 31702 (Lt. Col. R. H. Cunnington Coll.) 
Uppermost spathi Subzone, between Osmington Mills and Black Head, Dorset. 

Dimensions. 93 -40 -20 -30 (slightly crushed laterally) 

Remarks. This species differs from A . evolutus of the basal part of the intermedins 
Subzone, to which it is closely related, by possessing fainter and more distant ribbing 
but which are more regularly bifurcating. Although the Holotype is slightly crushed 
it is probably more compressed than A. evolutus. The short intercalated ribs on the 
ventro-lateral shoulders, absent in A. evolutus, are reminiscent of those seen in the 
much later Semenovites gracilis (Spath) of the varicosum Subzone (Upper Albian). 
These are taken to an extreme development in a form which occurs in the basal part 
of the intermedins Subzone at Caen Hill, Devizes (Bed 7) . Nonetheless, A . grimsdalei 
in fact links A. osmingtonensis and A. evolutus. 

Horizon and locality. Extreme top of the spathi Subzone in the Osmington 
area of Dorset, and at Petersfield, Hampshire (BMNH. C. 35482). 



152 



MIDDLE ALBIAN STRATIGRAPHY 



B. Stratigraphical List 

To conserve space, Subzones are numbered consecutively, (i) eodentatns, (2) lyelli, (3) spathi ; 
(4) intermedins, (5) niobe, (6) subdelaruei, (7) meandrinns ; (8) nitidus, (9) daviesi. p = premuta- 
tion. 



Phylloceratidae 

Hypophylloceras sp. ..... 

Lytoceratidae 

Pictetia astieriana (d'Orbigny) . , . 

Tetragonitidae 

Tetragonites kitchini (Krenkel) . . . 

Hamitidae 

Hamites (Hamiies) attenuatus J. Sowerby 

rotundns J. Sowerby . 

tenuicostatus Spath . 
compressus J. Sowerby . 
„ gracilis Spath. . 

gibbosus J. Sowerby . . 

snbrolundus Spath 
maximus J. Sowerby , 

tenuis J. Sowerby . . 

„ subacuaria Spath 
Anisoceratidae 
Protanisoceras {Protanisoceras) alternotubevculatum 

(Leymerie) 
„ „ barrense 

(Buvignier) 
„ „ nodoneum 

(Buvignier) 
„ „ moreanum 

(Buvignier) 
,» „ spp. 

„ (Heteroclinns) nodosum (J. Sowerby) 

,, ,, flexuosum (d'Orbigny) 

Metahamites sabtieri (d'Orbigny) . 

spp 

Turrilitidae 
Proturrilitoides densicostatus (Passendorfer) 
Pseudhelicoceras argonnensis (Buvignier) 
,, snbcatenatum Spath 

Binneyitidae ? 

Falciferella milbournei Casey 
Desmoceratidae 
Puzosia (Anapuzosia) provincialis (Parona & 

Bonarelli) 
XJhligella derancei Casey 

,, „ erugata Casey 

Beudanticcras laevigatum (J. de C. Sowerby) 
,, sanclaecrucis Bonarelli 

,, albense Breistroffcr . 

Desmoceras (Desmoceras) latidorsatam (Michelin) 



X 



X 



X 

X 

X 

X 
X 



X 



X 



X 
X 
X 
X 



■^ r 



X 



X 
X 



X 



X 

X 

X 
X 
X 
X 
X 



X 



X 



X 



X 



X 
X 
X 
X 
X 
X 
X 



X 
X 
X 
X 
X 
X 
X 



X 



IN THE ANGLO-PARIS BASIN 



153 







r ■ 




1 1 


\ 1 — 






1 


2 


34567 


Douvilleiceratidae 




















Douvilleiceras inaequinodum (Quenstedt) 


X 


















,, chmentinum (d'Orbigny) . 




X 
















Engonoceratidae 




















Engonoceras iris Spath .... 










X 










Hoplitidae 




















Cleoniceras (Cleoniceras) devisense Spath 


X 


X 
















Otohoplites spp. ...... 


X 


















„ ? cunningtoni Spath 


X 


















Hoplites (Isohoplites) steinmanni (Jacob) 


X 


















,, ,, eodentatus Casey 


X 


















spp 


X 


















„ (Hoplites) dentatus (J. Sowerby) 




X 


X 














,, „ ,, robusta Spath 




X 


X 














,, ,, ,, densicostata Spath 




X 


X 














,, ,, ,, sidcata Seitz 






X 














„ ,, baylei Spath 




X 
















„ ,, bullatus Spath . 




X 
















,, ,, benettianus (J. de C. Sowerby) 




X 
















„ ,, spathi Breistroffer 






X 














„ ,, persulcatus Spath 






X 














„ „ paronai Spath . 






X 














„ ,, maritimus Owen nov. 






X 














„ ,, mirabiliformis Spath . 






X 














,, ,, obtusus Spath . 






X 














„ ,, pringlei Spath . 






X 














,, ,, si mil is Spath 






X 














„ „ mirabilis Parona & Bonarelli 






X 














„ ,, vectensis Spath . 






X 














,, ,, latesulcatus Spath 






X 














„ „ escragnollensis Spath 






X 














„ ,, rudis Parona & Bonarelli . 






X 














,, ,, dorsetensis Spath 






X 














„ ,, canavarii Parona & Bonarelli 






X 














,, ,, canavariformis Spath 






X 


?x 












,, ,, pretethydis Spath 






X 


?x 












,, ,, dentatiformis Spath 










X 












spp. 




X 


X 


X 


X 


X 


X 








Anahoplites osmingtonensis Owen nov. 








X 












,, grimsdalei Owen nov. . 








X 












,, evohttus Spath . 








X 












,, mimeticus Spath 








X 












,, intermedins Spath 










X 












,, mantelli Spath . 










X 












,, praecox Spath 










X 












,, alternatus (Woodward) 










X 












„ planus (Mantell) 










X 


X 


X 


X 


X 


X 


„ ,, compressa Spath 










X 


X 


X 


X 


X 


X 


„ ,, inflata Spath . 










X 


X 


X 


X 


X 


X 


„ „ discoidea Spath 










X 


X 


X 


X 


X 


X 


„ „ sulcata Spath . 














X 








,, „ gracilis Spath . 


















X 


X 



*54 



MIDDLE ALBIAX STRATIGRAPHY 



Anahoplites splendens (J. Sowerby) 
,, pleitrophorus Spatli 

,, daviesi Spath 

,, ,, ornata Spath 

,, ,, clegans Spath 

sp. . 
Dimorplioplites niobe Spath . 
doris Spath . 
pinax Spath . 

,, elegdns Spath 
biplicatus (Mantell) 
hilli Spath 
perehgans Spath 
crassa Spath . 
parkinsoni Spath 
tethydis (Bayle) 

„ Spath non Bayle 
glaber Spath 
chloris Spath 
Euhoplites subtabulatus Spath 
pricei Spath 
loricatus Spath 
subtuberculatus Spath 
aspasia Spath 
microceras Spath . 
meandrinus Spath 
cantianus Spath . 
bilobits Spath 
beaneyi Milbourno 
truncatus Spath . 

,, quady at a Spatl' 
lautus (J. Sowerby) 

,, duntonensis Spath 
nitidus Spath 
opalinus Spath 
.proboscidelts (J. Sowerby) 

,, intermedia Spath 

buchlandi Spath . 

Lyelliceratidae 

Lyelliceras camatteanum (d'Orbigny) 

,, pseudolyeUi (Parona & Bonarelli) 

,, hirsuium (Parona & Bonarelli) 

,, huberianum (Pictet) 

,, lyelli (d'Orbigny) 

,, radenaci (Pervinquiere) 

,, colter i Spath 

,, gevreyi (Jacob) 

Brancoceras (Brancoceras) senequierl (d'Orbigny 
,, versicostatum (Michelin) 

>> » spp. 



t -\ t 




1 t — 




1 2 3 4 5 


6 7 


8 9 








X 


X 


X 


X 
X 


X 


X 

X 
X 
X 

X 








X 


X 


X 
X 
Xp 

Xp 


X 
X 
X 
X 
X 
X 
X 

?x 
x 


X 

X 
X 
X 
X 
X 


X 

X 

X 
X 
X 

X 








X 


















X 


X 
















X 


X 


X 


X 












X 


X 


X 


X 












X 


X 


X 


X 












X 


X 


X 


X 
X 
X 
X 
X 


X 
X 
X 
X 
X 
X 
X 
X 
X 


X 
X 
X 
X 

X 
X 
X 
X 
X 


X 


















X 
















X 
















X 


















X 


















X 


















X 


















X 


















X 


















X 
















X 


X 

















IN THE ANGLO-PARIS BASIN 



155 



Eubrancoceras (Eitbrancoceras) aegoceratoides 

(Steinmann 
„ „ cricki Spath 

spp. 
Mo j sisovicsiidae 

Oxytropidoceras evansi Spath 

„ voissyanum (d'Orbigny) 

,, mirapelianum (d'Orbigny) 

„ cf. carbonarium (Gabb) 

spp. . 
Mojsisovicsia delaruei (d'Orbigny) 

,, ,, compressa Spath 

„ subdelaruei Spath 

,, remota Spath . 

„ spinulosa Spath 

„ equicostata Spath 

Dipolocev.as corniitum (Pictet) 
F.alloticeras proteum (d'Orbigny) 



2 

X 
X 
X 

X 



3 4 



X 



X 
X 
X 
X 
X 
X 



X 



56789 



X 

X 



X 
X 
X 



X 



VIII. REFERENCES 

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160 MIDDLE ALBIAN STRATIGRAPHY 

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H. G. Owen B.Sc, Ph.D., F.G.S. 
Department of Palaeontology 
British Museum (Natural History) 
Cromwell Road 
London S.W.7 



PLATE i 



Anahoplites osmingtonensis sp. nov. 
Figs, i a, b. Lateral and peripheral views of holotype (BMNH. C 68385) X 1. Uppermost 
spathi Subzone, between Osmington Mills and Black Head, Dorset. 

Anahoplites grimsdalei sp. nov. 
Figs. 2 a, b. Lateral and peripheral views of holotype (BMNH. C 31702) X 1. Uppermost 
spathi Subzone, between Osmington Mills and Black Head, Dorset. 

Hoplites (Hoplites) maritimus sp. nov. 
Figs. 3 a, b. Lateral and peripheral views of holotype (BMNH. C 862a) X 1. Spathi Sub- 
zone, Lower Gault Bed I (v), Folkestone, Kent. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 8 



PLATE i 




PLATE 2 

Dentatus Zone Indices 
Hoplites (Isohoplites) eodentatus Casey 
Figs, i a, b. Lateral and peripheral views X i of an example from Bed i, eodentatus Subzone, 
Coney Hill Sand pit, Tandridge, Surrey. (BMNH. C 76480) 

Lyelliceras lyelli (d'Orbigny) 
Figs. 2 a, b. Lateral and peripheral views X 1 of an example from Division 2 (iv), lyelli Sub- 
zone, Horton Clay Pit, Upper Beeding, Sussex. (BMNH. C 76481) 

Hoplites (Hoplites) spathi Breistroffer 
Figs. 3 a, b. Lateral and peripheral views X 1 of a late mutation from Bed 4, upper part of 
the spathi Subzone, Buckland Sand & Silica Co. pit, Reigate, Surrey. (BMNH. C 76483) 

Hoplites (Hoplites) dentatus (J. Sowerby) 
Figs. 4 a, b. Lateral and peripheral views X 1 of a late mutation from the same bed and 
locality as Figs. 3 a, b. (BNMH. C 76482) 

(All specimens author's coll.) 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 8 



PLATE 2 




PLATE 3 

Loricatus and Lautus Zone Indices 
Euhoplites loricatus Spath 
Figs, i a, b. Lateral and peripheral views X i of a late form from Division 5 (ii), meandrinus 
Subzone, Sevenoaks Brick Works, Otford, Kent. (BMNH. C 76484) 

Anahoplites intermedins Spath 
Figs. 2 a, b. Lateral and peripheral views X 1 of a body chamber fragment from Division 3 
(iv), intermedins Subzone, same locality as Figs, i a, b. (BMNH. C 76485) 

Dimorphoplites niobe Spath 
Figs. 3 a, b. Lateral and peripheral views X 1 of an example from 4 inches below the top of 
Bed III, niobe Subzone. Folkestone, Kent. (BMNH. C 76488) 

Mojsisovicsia subdelaruei Spath 
Fig. 4. Two immature crushed individuals in a block of clay from 2 feet 2 inches above the 
base of Division 4, subdelaruei Subzone, Sevenoaks Brick Works, Otford, Kent. (BMNH. 
C 76486) 

Euhoplites meandrinus Spath 
Figs. 5 a, b. Lateral and peripheral views X 1 of a typical fragment from Bed IV (iii), 
meandrinus Subzone, Folkestone, Kent. (BMNH. C 76489) 

Euhoplites nitidus Spath 
Figs. 6 a, b. Lateral and peripheral views X 1 of an example from Bed V, nitidus Subzone, 
Folkestone, Kent. (BMNH. C 76490) 

Euhoplites lautus (J. Sowerby) 
Figs. 7 a, b. Lateral and peripheral views X 1 of a wholly septate phosphatic steinkern from 
the condensed ' lautus Zone nodule bed ' Division 6, Sevenoaks Brick Works, Otford, Kent. 
(BMNH. C 76487) 

Anahoplites daviesi Spath 
Figs. 8 a, b. Lateral and peripheral views X 1 of an involute form from the upper part of Bed 
VII daviesi Subzone, Folkestone, Kent. (BMNH. C 76491) 

(All specimens author's coll.) 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 8 



PLATE 3 




2 JAN* 97 * 



'v J 



A LIST OF SUPPLEMENTS 

TO THE GEOLOGICAL SERIES 

OF THE BULLETIN OF 

THE BRITISH MUSEUM (NATURAL HISTORY) 



4- 



5- 



Cox, L. E. Jurassic Bivalvia and Gastropoda from Tanganyika and Kenya. 
Pp. 213; 30 Plates; 2 Text-figures. 1965. £6. 

El-Naggar, Z. R. Stratigraphy and Planktonic Foraminifera of the Upper 
Cretaceous — Lower Tertiary Succession in the Esna-Idfu Region, Nile Valley, 
Egypt, U.A.R. Pp. 291; 23 Plates; 18 Text-figures. 1966. £10. 
Davey, R. J., Downie, C, Sargeant, W. A. S. & Williams, G. L. Studies on 
Mesozoic and Cainozoic Dinoflagellate Cysts. Pp. 248; 28 Plates, 64 Text- 
figures. 1966. £7. 

Appendix. Davey, R. J., Downie, C, Sargeant, W. A. S. & Williams, G. L. 
Appendix to Studies on Mesozoic and Cainozoic Dinoflagellate Cysts. Pp. 24. 
1969. 16s. 

Elliott, G. F. Permian to Palaeocene Calcareous Algae (Dasycladaceae) of the 
Middle East. Pp. hi; 24 Plates, 17 Text-figures. 1968. £5 2s. 6d. 
Rhodes, F. H. T., Austin, R. L. & Druce, E. C. British Avonian (Carboniferous) 
Conodont faunas, and their value in local and continental correlation. Pp. 315; 
31 Plates, 92 Text-figures. 1969. £11. 

Childs, A. Upper Jurassic Rhynchonellid Brachiopods from Northwestern 
Europe. Pp. 119; 12 Plates, 40 Text-figures. 1969. £4 15s. 
Goody, P. C. The relationships of certain Upper Cretaceous Teleosts with special 
reference to the Myctophoids Pp. 255 ; 102 Text-figures. 1969. £6 10s. 



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Q. A. SIDDIQUI 



BULLETIN OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 
GEOLOGY Supplement 9 

LONDON: 1971 



EARLY TERTIARY OSTRACODA OF THE 

FAMILY TRACHYLEBERIDIDAE FROM 

WEST PAKISTAN 



BY 



QADEER AHMAD SIDDIQUI 

University of Leicester 



42 Plates, 7 Text-figures 




BULLETIN OF 

THE BRITISH MUSEUM (NATURAL HISTORY) 

GEOLOGY Supplement 9 

LONDON : 1971 



THE BULLETIN OF THE BRITISH MUSEUM 

(natural history), instituted in 1949, is 
issued in five series corresponding to the Departments 
of the Museum, and an Historical series. 

Parts will appear at irregular intervals as they become 
ready. Volumes will contain about three or four 
hundred pages, and will not necessarily be completed 
within one calendar year. 

In 1965 a separate supplementary series of longer 
papers was instituted, numbered serially for each 
Department. 

This paper is Supplement 9 of the Geological 
(Palaeontological) series. The abbreviated titles of 
periodicals cited follow those of the World List of 
Scientific Periodicals. 



World List abbreviation 
Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 



Trustees of the British Museum (Natural History) 1971 



TRUSTEES OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 

Issued 23 February, 1971 Price £8 



EARLY TERTIARY OSTRACODA OF THE 
FAMILY TRACHYLEBERIDIDAE FROM 
WEST PAKISTAN 

By Q. A. SIDDIQUI 



CONTENTS 

I. Introduction 
II. Acknowledgments . 

III. LlTHOLOGICAL UNITS 

IV. Systematic descriptions 

Subclass Ostracoda Latreille 
Order Podocopida Miiller 
Suborder Podocopina Sars 
Superfamily Cytheracea Baird 

Family Trachyleberididae Sylvester-Bradley 
Genus Actinocythereis Puri 

Actinocythereis ? quasibathonica sp. nov 
Genus Alocopocythere nov. 

Alocopocythere transcendens sp. nov. 
Alocopocythere rupina sp. nov. 
Alocopocythere abstracta sp. nov. 
Alocopocythere coarctata sp. nov. 
Alocopocythere longilinea sp. nov. 
Alocopocythere transversa sp. nov. 
Alocopocythere radiata sp. nov. 
Genus " Anommatocy there " Sohn 

" Anommatocy there " laqueta sp. nov. 
" Anommatocythere " confirmata sp. nov. 
Genus Bradley a Hornibrook . 

Bradleya ? voraginosa sp. nov. 
Genus Buntonia Howe 
Buntonia devexa sp. nov 
Buntonia sp. A 
Genus Costa Neviani 
Subgenus Paracosta nov. 

Costa (Paracosta) declivis sp. nov. 
Costa (Paracosta) compitalis sp. nov. 
Costa (Paracosta) disintegrata sp. nov 
Genus Echinocythereis Puri 

Subgenus Echinocythereis sensu stricto 

Echinocythereis (Echinocythereis) contexta sp. nov 

Echinocythereis (Echinocythereis) elongata sp. nov 

Subgenus Scelidocythereis nov. 



Page 

5 

7 

8 

io 

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IO 
IO 
IO 
IO 
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IO 

J3 
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EARLY TERTIARY OSTRACODA 



Echinocythereis (Scelidocythereis) multibullata sp 
nov. ....... 

Echinocythereis (Scelidocythereis) sp.A 

Echinocythereis (Scelidocythereis) rasilis sp. nov 

Echinocythereis (Scelidocythereis) sparsa sp. nov 
Genus Gyrocythere nov. 

Gyrocythere exaggerata sp. nov. 

Gyrocythere parvicarinata sp. nov. 

Gyrocythere grandilaevis sp. nov. 

Gyrocythere mitigata sp. nov. 

Gyrocythere perfecta sp. nov. 
Genus Hermanites Puri 

Hermanites cracens sp. nov. 

Hermanites scopus sp. nov. 

Hermanites palmatus sp. nov. . 
Genus Occultocythereis Howe . 

Occultocythereis interrupta sp. nov. 

Occultocythereis sp.A 

Occultocythereis spilota sp. nov. 

Occultocythereis peristicta sp. nov. 

Occultocythereis indistincta sp. nov. 
Genus Patagonacy there Hartmann . 

Patagonacy there ? nidulus sp. nov. 
Genus Phalcocythere nov. 

Phalcocythere horrescens (Bosquet) 

Phalcocythere improcera sp. nov. 

Phalcocythere rete sp. nov. 

Phalcocythere retispinata sp. nov. 

Phalcocythere sentosa sp. nov. . 

Phalcocythere dissenta sp. nov. . 

Phalcocythere spinosa sp. nov. . 

Phalcocythere sp. cf. P. spinosa 
Genus Quadracythere Hornibrook 
Subgenus Hornibrookella Moos 

Quadracythere (Hornibrookella) platybomus sp. nov 

Quadracythere (Hornibrookella) directa sp. nov 

Quadracythere (Hornibrookella) arcana (Lubimova 
and Guha) 

Quadracythere (Hornibrookella) subquadra sp. nov 

Quadracythere (Hornibrookella) sp.A 
Genus Stigmatocythere nov. 

Stigmatocy there obliqua sp. nov. 

Stigmatocythere portentum sp. nov. 

Stigmatocythere calia sp. nov. 

Stigmatocythere delineata sp. nov. 

Stigmatocythere lumaria sp. nov. 
Genus Trachyleberis Brady 

Subgenus Trachyleberis sensu stricto 

Trachyleberis (Trachyleberis) lobuculus sp. nov. 

Trachyleberis (Trachyleberis) biniammillata sp. nov 
Subgenus Acanthocythereis Howe 

Trachyleberis (Acanthocythereis) procapsus sp. nov 

Trachyleberis (Acanthocythereis) usitata sp. nov. 

Trachyleberis (A canthocythereis) pedigaster sp. nov 



34 
35 

36 
37 
38 
39 
40 

4i 
42 
43 
44 
44 
45 
47 
48 
48 
49 
49 
50 
53 
54 
54 
56 
57 
58 
59 
60 
61 
62 

63 
64 

65 
65 
65 
66 

67 
68 
69 
69 
70 
72 
73 
74 
75 
77 
77 
77 
78 
80 
80 
81 
81 



FROM WEST PAKISTAN 5 

Trachyleberis (Acanthocythereis) postcornis sp. nov. 82 

Trachyleberis {Acanthocythereis) decoris sp. nov. . 83 
v. ostracoda and early tertiary correlation in the sulaiman 

Range .......... 85 

(a) Biostratigraphic Units ....... 85 

(b) Statistical Correlation of ranges of ostracod species common to 

the Rakhi Nala and Zao River sections .... 89 

(c) Conclusions . . . . . . . . .91 

VI. Appendices ......... 93 

VII. References .......... 95 

Tables, and Rakhi Nala and Zao River Sections In pocket on 

Cover p. iii 

SYNOPSIS 

Ostracoda from the Palaeocene of the Sor Range and from the Palaeocene and Eocene of the 
Rakhi Nala, Zao River and Shpalai Khwara sections, Sulaiman Range, West Pakistan, have 
been examined. The family TRACHYLEBERIDIDAE has been studied in detail. It is 
represented by fourteen genera, four subgenera and fifty-nine species. Four new genera 
{Alocopocy there, Gyrocy there, Phalcocythere and Stigmatocy there) and two new subgenera (Para- 
costa and Scelidocythereis) are proposed. Out of the fifty-nine species described, fifty-four are 
new. Two species belonging to the genus Phalcocythere one from the Paris Basin and the other 
from Tanzania are also described. 

The Palaeocene and Eocene of the Rakhi Nala section are divided into five ostracod bio- 
stratigraphic units. The biostratigraphic units IV and V of the Rakhi Nala are represented in 
the Zao River section and have almost identical ostracod faunas. The biostratigraphic unit 
IV of the Rakhi Nala is also represented in the Shpalai Khwara section. The Equations of 
Correlation between the Rakhi Nala and Zao River sections for biostratigraphic unit V (i. e. 
Middle-Upper Eocene) have been calculated by means of ranges of ostracod species common to 
the two sections. The standard errors of estimate for the Equations of Correlation have also 
been calculated. The boundaries between the Palaeocene-Lower Eocene, Lower-Middle 
Eocene and Middle-Upper Eocene in the Sulaiman Range are discussed. 

1. INTRODUCTION 

The most comprehensive work so far published on the area is that of Eames (1952 ab). 
Most of his lithological subdivisions for the Eocene succession of the Rakhi Nala and 
Zinda Pir areas occur in the northern Sulaiman Range, i.e. in the Zao River and 
Shpalai Khwara sections. These can easily be distinguished on the basis of lithology 
and micro fauna. Eames' terminology of the rock units is therefore adopted here. 
Bayliss (1961) and Latif (1961 and 1964) are other recent workers who have con- 
tributed to our knowledge of the Palaeocene and Eocene in the Rakhi Nala section. 
However, they used a different terminology for the rock units to that used by 
Eames, and Fig. 2 shows the correlation between these workers along the Rakhi Nala 
section. 

The samples from the Rakhi Nala section examined for ostracods were the same as 
used by Bayliss and Latif, who worked on larger and pelagic foraminifera respect- 
ively. These samples were collected by Bayliss. The sample numbers as given by 
the collector are used in this paper. Latif altered the sample numbers after 3200 by 
subtracting two hundred, i.e. his sample no. 3201 is the same as collector's no. 3401, 
and so on. 



EARLY TERTIARY OSTRACODA 




AB Zao River Section 
CD. Shpalai Khwara Section 
EF Rakhi Nala Section 
G. Sor Range Section 
r .''•.*( I Eocene Outcrops 



Outcrops of Eocene rocks of part of West Pakistan. 
(After Eames 1952.) Sections described are indexed. 

FIG.1 



5 



I" 

"O o 

-* LU 



O 

o 
a. 



Correlation between Eames, Bayliss and Latif along the Rakhi Nala 



Eames ( 1952, p.162-163 ) 



& 



Succession 



Pellatispira Beds 



Upper Chocolate Clays (Upper part) 



c 


._ 


w 




u 

o 


a 




n 




CI 






w 




S 


" 


o 


J£ 



CARDIU 

beaumomi 

BEDSt 



Upper Chocolate Clays ( Lower part) 



White Marl Band 



Lower Chocolate Clays 



Platy Limestone 



Shales with Alabaster 



Rubbly Limestones 



Green and Nodular Shales 



Upper Rakhi Gaj Shales 



Lower Rakhi Gaj Shales. (Topmost 

portion onlyS Irregularis Limestone, 



Lower Rakhi Gaj Shales (Max pars) 



Gorge Beds 



Venericardia Shales 



Thickness 
in feet 



Sample no. 

as used in 

present 

paper 



60 



425-495 



420-490 



40 



930 



70 



750 



410 



850 



1620 



60 



775 



470 



95 



3666 
3657 



K38 
3413 



36.67 
3668 



3667.367! 
3139 

3,t 



3115 
3110 



Bayliss & SamantaOn press) 



Succession 



Kirthar 



Ghazij 



Dunghan 



Ranikot 



6> 

D.C 
i <■> 

slS 



o 

LU 



O 

a. 



Thickness 

in feet & 

sample nos. 



2212 



3607 



759 



3,15 

553 3no 



Latif (1961, p. 33-36,1964, p. 31) 



Thickness 

in feet & 

sample nos 



110 

2m 



3664 
3651 



A25 



K0 
170 



160 



360G 
3498 



900 



100 



1160 



670 



30 



100 



ur 



240 



850 



1840 



Zones 



Globigerina cf. trilocula 

Chiloouembelina victoriana 



Hastiqerina micro 



Chiloquembelina att martini 



Catapsvdrax unicavus 



Globigerina yequaensis 



No Pelagic foraminifera 



Globorotalia sp. 3 



Globorotalia sp. 4 



Globigerina esnaensis 



Hastigerina pseudoiota 



Globigerina sp. 5 



Globorotalia rex 



Globorotalia (T ) crater 



Globorotalia angulata 



No Pelagic foraminifera 



Succession 



Tapti 



Kirthar 



Ghazij 



Ranikot 



Pab Sandstones 



Pab 



Pab 



* Probable equivalents of Eames, 1952. 

**Eames, personal communication. 

+ Danian according to Nagappa, 1959, which he regards as basal Paleocene. 
*■ ? Paleocene. 



FIG. 2 



FROM WEST PAKISTAN 7 

Samples from the Zao River and Shpalai Khwara sections were taken by S. M. 
Ahmed and W. A. Zuberi and those from the Sor Range section by J. A. Reinemund. 

All specimens with the prefix Io. are in the Department of Palaeontology, British 
Museum (Natural History) . Those with the prefix GSP BM are in the Museum of the 
Geological Survey of Pakistan, Cjuetta. 

II. ACKNOWLEDGMENTS 

I would like to express my sincere gratitude to Professor P. C. Sylvester-Bradley 
for his supervision, encouragement, constant help throughout this work, and for the 
use of the Department facilities at Leicester University. I am greatly indebted to 
Dr. F. E. Eames, lately Chief Palaeontologist of the British Petroleum Company Ltd., 
for his help and advice on the stratigraphy, particularly that of the Sulaiman Range, 
and for allowing me to examine East African Eocene ostracod collections at the BP 
Research Centre. Thanks are due especially to Dr. E. Triebel of the Senckenberg 
Museum, Frankfurt a.M., for his instructions in photomicrography and for kindly 
permitting me to study the ostracod collection at the Museum. During my several 
visits to the British Museum (Natural History), I have been received with courtesy 
by Dr. J. P. Harding and Dr. R. H. Bate, who gave me free access to the ostracod 
collections under their care. In addition, Dr. R. H. Bate read the manuscript 
critically. I have profited from useful discussions with Professor R. A. Reyment 
which I had while on a study tour to Stockholm. He kindly allowed me to see his 
West African ostracod collection. Dr. P. Marks helped me during my stay at 
Utrecht and gave me free access to the van den Bold, Kingma and Keij Collections 
housed in the Geologisch Instituut. 

I should like to thank Dr. F. T. Banner (University College, Swansea) for examin- 
ing some of the smaller foraminifera from the Rakhi Nala and Sor Range sections ; 
Dr. C. G. Adams (British Museum, Natural History) for his help in identifying the 
genus Pellatispira from the Zao River ; and Mr. J. A. Reinemund (U.S. Geological 
Survey) for the information on the Sor Range locality. 

For the loan of samples, I am indebted to the following : Standard Vacuum Oil 
Company, Karachi ; The Director, Geological Survey of Pakistan, Ouetta ; Dr. I. 
Strachan, Birmingham University ; Dr. D. D. Bayliss, Robertson Research Ltd. 
I would like to acknowledge the following persons for comparative material : Mr. E. S. 
Pinfold, Geological Adviser of the Attock Oil Co. Ltd. ; Dr. F. E. Eames, lately Chief 
Palaeontologist of the British Petroleum Co. Ltd. ; Mr. I. G. Sohn, U.S.A. ; Pro- 
fessor A. Wood, Aberystwyth ; The Director, Oil and Gas Commission, India ; Dr. 
W. A. van den Bold, U.S.A. ; Dr. W. D. I. Rolfe, of the Hunterian Museum, Glasgow ; 
Dr. N. Grekoff, France ; Dr. R. C. Whatley, Aberystwyth ; Dr. J. E. van Hinte, 
Holland ; and Professor G. Ruggieri, Italy. 

I would like to thank the departmental technical staff at Leicester University, 
particularly Mr. M. Barker and Mr. G. McTurk for their assistance in photography. 
I am very grateful to Mrs. N. Farquharson for making the diagrams and charts. 

This work has been done during the tenure of a Leicester University Research 
Scholarship. The study tours to Frankfurt, Utrecht and Stockholm were made 
possible by two travelling grants from the Leicester University Research Board. 



8 EARLY TERTIARY OSTRACODA 

III. LITHOLOGICAL UNITS 

Sulaiman Range. The lithological units of the Rakhi Nala section have been 
described in detail by Eames (1952, pp. 162-165), Bayliss (1961) and Latif (1961, 
p. 32). Fig. 2 shows the succession, and the formation names give some idea of the 
lithology ; for a fuller description, see the authors mentioned above. The Eocene 
succession in the Zao River and Shpalai Khwara sections (Fig. 3) is very similar to 
that of the Rakhi Nala section. A detailed lithological description of rocks exposed 
along the Rakhi Nala, Zao River and Shpalai Khwara sections is given by means of 
two charts. 



ZAO RIVER 



SHPALAI KHWARA 



Succession 



Thickness 
in feet 



Sample 
nos. 



Thickness 
in feet 



Sample 
nos. 



c 

o 
o 

LU 



a. 
a. 

ID 



c 

(J 
o 

LU 
T3 



in 

h *» 

9 E 

■C ,0 

-£ ID 

5 o 



Q. <• 

D - 



Upper Chocolate Clays (Upper part) 



1796 



a e 

.c ° 

k ° 

u 

o t 
-I X 



Upper Chocolate Clays (Lower part) 



910 



White Marl Band 



86 



Lower Chocolate Clays 



754 



Platy Limestone 



178 



24210 

1 



24161 



24160 



24138 



24134 



24133 



24120 



24119 

?41K 



Q 
LU 
CO 

o 
a. 

X 

LU 



A0 



24696 
24694 



m 



M. 



Shales with Alabaster 



at least 
332 



24113 
24 T 097 



at least 
320 



24^93 
24675 



Part of the Eocene Succession in the Northern Sulaiman Ran ge. 

FIG. 3 



Sor Range. Samples were collected from the " Claystones " which are overlain by 
fifty feet of conglomerates. The Ghazij Shales overlie the conglomerates. A chart 
showing these lithological units is given (Fig. 6), and a detailed succession is given in 
Appendix 1. " The locality is in Lease 58 on the north slope of the Sor Range, about 
eight miles by road east of Quetta (Survey of Pakistan Topo. Sheet No. 34 N/4, co- 
ordinates 30 n'20" N., 67 10' E, grid reference P 125210). Samples were collected 
from a road cut along the main access road that crosses the lease approximately 
parallel with the outcrop and along the contour of the slope ; structurally the locality 



FROM WEST PAKISTAN 




io EARLY TERTIARY OSTRACODA 

is near the northern end of the Sor Range syncline, which is the major structural 
feature of the Sor Range-Danghari coalfield. " (Reinemund, personal communi- 
ication 1966). 

Dr. F. T. Banner of University College, Swansea, was kind enough to examine 
smaller foraminifera from sample 460-i. He has dated this horizon as the Upper 
Palaeocene (pseudomenardii Zone). 

IV. SYSTEMATIC DESCRIPTIONS 

Subclass OSTRACODA Latreille 1806 

Order PODOCOPIDA Muller 1896 

Suborder PODOCOPINA Sars 1866 

Superfamily CYTHERACEA Baird 1850 

Family TRACHYLEBERIDIDAE Sylvester-Bradley 1948 

Diagnosis. Cytheracea with heavily calcified carapace, often highly ornamented 
with more or less conspicuous eye-tubercle. Muscle scar pattern basically consisting 
of four adductor scars (one or more vertically divided in some genera) with a 
frontal scar which may be simple, V-Shaped, U-shaped or multiple. Posterior 
characteristically sub-triangular or auricular, but in some genera produced to form a 
caudal process. Subcentral-tubercle present or absent. 

Remarks. The classification adopted here is to retain the trachyleberids and the 
hemicytherids in the family Trachyleberididae. Although in general trachyleberids 
possess a subcentral-tubercle and a V-shaped frontal scar whilst hemicytherids 
possess divided frontal and adductor scars, an auricular posterior end but lack the 
subcentral-tubercle there still remain a large number of genera which tend to overlap, 
thus making it impossible to clearly define the groups at the present time. Hazel 
(1967) identified two families, the Trachyleberididae having six podomeres in the 
antennule and the Hemicytheridae with five podomeres. This morphological 
character is useless palaeontologically and considering the number of trachyleberids 
which share hemicytherid characters (e.g. divided frontal scars) and hemicytherids 
having a subcentral-tubercle it would appear optimistic to expect the number of 
podomeres in the antennule to be so unique as to be restricted to only one group when 
other, equally good morphological characters obviously are not. 

Pokorny (1964) considered*the Hemicytherinae to be a group having a horizontal 
classification, and the situation at the present time has not been effectively clarified. 

Genus ACTINOCYTHEREIS Puri 1953 
Type species. Cythere exanthemata Ulrich and Bassler 1904 

Actinocythereis ? quasibathonica sp. nov. 
(Plate 1, figs. 1-3, 6, 7, 10-13) 

Derivation of name. Latin quasibathonica, " simulating Bathonian " ; with 
reference to the resemblance to the Middle Jurassic (Bathonian) genus Oligocythereis. 




Trocad from topo sh««t No. 3i It,. 



Scale 1:50,000 



Furlongs 8 6 4 2 



MAP OF PART OF SOR RANGE SHOWING FOSSIL LOCALITY, QUETTA DIVISION, WEST PAKISTAN. 

FIG. 5 



FROM WEST PAKISTAN 
SOR RANGE SECTION 
Measured by John A. Reinemund 



Kirthar formation 



* T T i Tf 



ill 






Ghazij formation 



33-?3 1600 ( a PP r ox) 



a o a ° « 



o O, 

°«° 

O°0 



a 

O 
o o ° 

o o 

O c 

> o 

O o 



Middle Eocene 



Lower Eocene 



r50Ft 



460a 
460b 

--::- zj-460c 



L 



V-r Limestone 



gjg] Claystone 

Conglomerate 
Sandstone 



}460d 

460e 
460f 



Pseudomenardii zone 
(high Palaeocene) 



-460g 
-=-:>|~460h 
>-lH-460 i 

r 460j 



Upper Palaeocene 



--I±-- 460k 
----- >- 460 1 /rn , 



460o 




Base not exposed 
FIG. 6 



EARLY TERTIARY OSTRACODA 



Diagnosis. Medium size, thick shelled. High and distinct anterior marginal 
rim with posterior ornamentation. Surface sparsely punctate. Subcentral tubercle 
prominent and rounded. 

Holotype. Io. 4311, a female carapace (PI. I, Figs. 2, 3, 11, 12). 

Paratypes. Io. 4260 + Io. 3100-1. 

Material. 29 specimens from the Rakhi Nala section from 8 horizons (sample 
nos. 3610, to 3615, 3617, 3618 and 3620). 10 specimens from the Zao River section 
from two horizons (sample nos. 24150 and 24154). GSP BM 2506-7. 

Type locality. Rakhi Nala section. 

Type horizon. Upper Chocolate Clays, sample no. 3611. 

Description. Sexual dimorphy moderate, the females are higher and wider than 
the males. Carapace sub-rectangular, medium size and thick shelled. Anterior 
margin broadly rounded, postero-dorsal margin slightly concave, posterior extremity 
and postero-ventral margin somewhat rounded. Dorsal and ventral margins almost 
straight, slightly tapering towards the posterior. In lateral view the dorsal orna- 
mentation over-reaches the dorsal margin. Valves almost equal. In dorsal view 
the greatest width passes through the sub-central node. Eye-tubercle rounded, 
prominent and situated below and slightly anterior to a well-developed anterior 
cardinal angle. Anterior marginal rim high. Ventral and posterior marginal rims 
less high. Sub-central tubercle prominent, rounded and distinct. Surface sparsely 
punctate (punctation is not distinct in some specimens), with an alate ventral ridge 
which slightly slopes upwards towards the posterior. The postero-dorsal process is 
a blade-like projecting ridge over-reaching the dorsal margin and extending vertically 
below for a short distance. A prominent mid-dorsal tubercle with a small tubercle 
present in front. There is also a small tubercle posterior and at some distance from 
the sub-central node. About 12 short marginal spines anteriorly, partly concealed 
in external lateral view by the anterior marginal rim, and 5-6 spines posteriorly. 
Radial pore canals few, simple and straight. Inner margin and line of concrescence 
coincide. Duplicative moderately wide. Selvage well marked lying sub-peripheral 
in left valve, but at some distance from the outer margin in right valve. There is a 
fairly well-developed flange groove in right valve. Muscle scars unknown. Hinge 
holamphidont with the details given below : 

Left Valve 

Socket 

Subcorneal tooth 

having a straight 

anterior and a convex 

posterior in dorsal 

view 

Denticulate bar 

Slightly elongate 

socket, open on 

venter. 



Hinge element 

Anterior 

Anteromedian 



Right Valve 

Conical projecting tooth 

Deep socket 



Posteromedian 
Posterior 



Shallow locellate groove 
Pessular tooth 



H 


w 


0-29 


0-27 


0-32 


0-29 


0-29 


■ — ■ 


0-29 


— 



FROM WEST PAKISTAN 13 

Dimensions (mm). 

L 
Io. 4260 Carapace male 0-51 

Io. 4311 Carapace female (holotype) 0-52 

Io. 3101 Left valve male 0-51 

Io. 3100 Right valve male 0-51 

Remarks. This species is tentatively assigned to the genus Actinocythereis. It 
differs from the type species of the genus in having a continuous rather than a 
broken ventral ridge. In addition, the present species is much smaller, has a pitted 
surface and fewer radial pore canals. 



Genus ALOCOPOCYTHERE nov. 

Derivation of name. Greek alokos, = furrow, opos = eye ; with reference to the 
furrow behind the eye-tubercle + cythere. 

Diagnosis. Trachyleberididae in which the eye-tubercle is confluent with both 
the elevated marginal rim and a short almost vertical ridge, delimited posteriorly by 
a deep furrow. Anterior and posterior cardinal angles protruding in left valve, only 
anterior cardinal angle protruding in right valve. Posterior cardinal angle of right 
valve over-reached by protruding cardinal angle of left valve. Dorsal margin 
humped. 

Type species. Alocopocythere transcendens sp. nov. 

Description. Dimorphic, the males are proportionally longer than the females. 
Carapace sub-rectangular to sub-quadrate in shape. Dorsal margin in lateral view 
sinuous, dominated by protruding anterior and posterior cardinal angles, with a 
hump between, ventral margin evenly curved or almost straight. Anterior margin 
broadly rounded, posterior straight or very slightly concave in postero-dorsal margin 
(between posterior cardinal angle and posterior extremity) ; posterior extremity 
rounded, postero-ventral region rounded or straight. Valves almost equal in size. 
Sub-central tubercle and eye-tubercle more or less distinct. Surface ornamentation 
either reticulate (with or without superimposed lineations or with superimposed 
papillae) or papillose. A marginal rim always present, usually upstanding anteriorly, 
less high along venter and posterior. Anterior and posterior margins ornamented 
with small spines or denticles. Normal pores simple, widely spaced. Radial pore 
canals simple, almost straight, often slightly inflated towards the middle, tending to 
occur in groups of two or three, often apparently crossing one another, about 32-35 
anteriorly and 18-20 posteriorly. Inner margin and line of concrescence coincide. 
Duplicature of moderate width. Selvage well-marked — sub-peripheral in left valve 
but at some distance from the outer margin in the right valve. Right valve with a 
deep flange groove on the centre and anterior. Muscle scar pattern consists of four 
adductors in a vertical row situated on the posterior margin of the muscle scar pit 
and an oval frontal scar with two more or less rounded mandibular scars below. 
Hinge holamphidont. Right valve with highly projecting, stirpate anterior tooth, 



i 4 EARLY TERTIARY OSTRACODA 

postjacent socket, posteromedian locellate groove and a pessular posterior tooth ; 
left valve with anterior socket, anteromedian sub-conical tooth, postero-median 
denticulate bar and a deep posterior socket. 

Comparison. This genus differs from Echinocythereis in having a short vertical 
ridge below and a furrow behind the eye-tubercle, also there are two frontal scars in 
Echinocythereis, but only one in Alocopocythere. Stigmatocythere has a curved ridge 
joining the eye-tubercle and the sub-central tubercle, whereas in Alocopocythere a 
short, almost vertical ridge joins the eye-tubercle and is delimited posteriorly by a 
furrow. Henryhowella has three longitudinal plications in the posterior half of the 
valve and an anterior vestibule, not present in Alocopocythere. Moreover, the 
frontal scar in Henryhowella is V-shaped, while Alocopocythere has an oval frontal 
scar. 

Remarks. In addition to the species described here, the Miocene species Trachy- 
leberis fossularis Lubimova and Guha (i960, p. 40, pi. 3, fig. 7), which Guha in 1961 
(p. 4, figs. 5, 9) transferred to the genus Echinocythereis should be ascribed to Alo- 
copocythere. 

Alocopocythere transcendens sp. nov. 
(Plate 1, figs. 4, 5, 8, 9 ; Plate 2, figs. 1-4, 6, 7) 

Derivation of name. Latin, transcendens, rising above ; with reference to the 
stratigraphic position in relation to A . abstracta. 

Diagnosis. Strongly reticulate Alocopocythere with rounded postero-ventral 
margin, sub-central tubercle more or less distinct, eye-tubercle distinct, marginal 
rim well marked. 

Holotype. Io. 4315, a female left valve (PI. 2, figs. 1, 6). 

Paratypes. Io. 4261 + Io. 3104-6. 

Material. 263 specimens from the Zao River section from 7 horizons (sample 
nos. 24127, 24131, 24132, 24145, 24147, 24148 and 24151). Approximately 600 
specimens from the Rakhi Nala section from 46 horizons (sample nos. 3168, 3198, 
to 3200, 3401 to 3405, 3407, 3409, 3410, 3418, to 3422, 3424, 3426, 3428, 3429, 3432, 
3434. 3435. 3438, 3457 to 3459. 349$, 3499. 3607, 3614, 3615. 3617 and 3618). GSP. 
BM. 2508. 

Type locality. Zao River section. 

Type horizon. Upper Chocolate Clays, sample no. 24148. 

Description. Carapace sub-rectangular to sub-quadrate in lateral outline. 
Sexual dimorphism rather marked, the females being shorter, higher and wider than 
the males. Dorsal margin sinuous with protruding anterior and posterior cardinal 
angles, ventral margin almost straight in the right valve but evenly curved in the 
left valve. Anterior margin broadly rounded, postero-dorsal margin very slightly 
concave particularly in the right valve, posterior extremity rounded, postero- 
ventral margin rounded. Valves almost equal in size. Eye-tubercle distinct, rounded 
and polished. Sub-central tubercle more or less distinct. Shell surface strongly 



FROM WEST PAKISTAN 



15 



reticulate. Antero-dorsal furrow deep, bounded anteriorly by a short almost 
vertical ridge joining the eye-tubercle. Anterior marginal rim high, continuing as a 
less high rim round the venter and posterior. Anterior margin ornamented with 
8-10 short spines, posterior with a postero-ventral spine, although these are pre- 
served in a few specimens only. Duplicature moderately wide, 0-073 mm. anteriorly 
in right valve female. Selvage prominent in both valves, situated in the outer third 
of the duplicature in right valve but sub-peripheral in left valve. Along the venter 
it is markedly concave antero-medially. Right valve has well-developed ventral 
and anterior flange grooves. Normal pore canals simple, small. Radial pore canals 
more or less straight, simple, some in groups of two or three, frequently crossing each 
other. There are approximately 35 radial pore canals in the anterior and 20 in the 
posterior. Line of concrescence and inner margin coincide throughout. Muscle 
scars consist of sub-vertical row of four adductors, situated on the posterior margin 
of the muscle scar pit, with an oval frontal scar and two somewhat rounded mandi- 
bular scars below. Hinge holamphidont with the following details : 



Element 
Anterior 



Anteromedian 



Posteromedian 
Posterior 



Left valve 

Deep socket confluent 
with ocular sinus, 
bounded on all sides. 
Subcorneal tooth with 
straight anterior and 
convex posterior in 
dorsal outline. 
Denticulate bar 
Deep slightly elongate 
socket open on ventral 
side. 



Right valve 
Highly projecting 
stirpate tooth, ocular 
sinus lies below it. 
Deep rounded socket 
opening into postero- 
median groove 

Locellate groove 
Pessular tooth, high 
on posterior tending 
towards reniform. 





L 


H 


w 


Carapace male 


072 


o-43 


0-42 


Left valve female (holotype) 


0-63 


0-44 


— 


Right valve female 


0-64 


o-39 


— 


Left valve female 


o-59 


o-39 


— 


Right valve male 


0-63 


0-38 


— 



Dimensions (mm). 

Io. 3104 

lo. 4315 
Io. 3105 
Io. 4261 
Io. 3106 

Comparison. Alocopocythere abstracta sp. nov. is a very closely related species, 
but is more elongate, and has a straight rather than rounded posteroventral margin 
and less deep reticulations. Alocopocythere transcendens is perhaps ancestral to 
Alocopocythere transversa sp. nov. but is smaller, and lacks the posterior concentric 
ridges and a short ridge in the anteroventral area. Alocopocythere fosstdaris (Lubi- 
mova and Guha) (i960) from the Miocene of Kutch is a similar species but which 
differs however, in the lateral outline of the carapace. 

Remarks. Specimens of A. fossularis (Lubimova and Guha) from the type 
locality in Kutch were not available for comparison. 



16 EARLY TERTIARY OSTRACODA 

Alocopocy there rupina sp. nov. 
(Plate 2, figs. 5, 8-10 ; Plate 3, figs. 1-4) 

Derivation of name. Latin, rupina, " chasm " ; with reference to the antero- 
dorsal furrow and associated ridges. 

Diagnosis. Alocopocythere in which anterodorsal furrow is delimited anteriorly 
by a short almost vertical ridge and posteriorly by the anterior part of the dorsal 
ridge. Surface reticulate with seven longitudinal ridges. Anterior and posterior 
plains almost smooth. 

Holotype. Io. 4314, a male carapace (PI. 2, figs. 5, 8-10). 

Paratype. Io. 4262. 

Material. 41 specimens from the locality below from one horizon (sample no. 
3111). GSP BM 2509-10. 

Type locality. Rakhi Nala section. 

Type horizon. Gorge Beds, sample no. 3111. 

Description. Sexual dimorphism strong, the males are longer than the females. 
Carapace subrectangular in lateral view. Dorsal margin sinuous, ventral margin 
slightly concave in front of the middle, anterior margin broadly rounded, posterior 
narrowly rounded. Anterior cardinal angle protruding particularly in right valve, 
posterior cardinal angle less well-developed. Left valve slightly over-reaches right 
valve at anterior cardinal angle and in the region of posterodorsal corner. Eye- 
tubercle rounded and distinct. Subcentral-tubercle well-developed. Surface orna- 
mentation with seven longitudinal ridges ; the dorsal ridge begins above and very 
slightly to the anterior of the subcentral-tubercle and is convex in the middle 
culminating in the posterior quarter. The four ridges below the dorsal ridge are 
almost confined posterior to the subcentral-tubercle, the second ridge from the centre 
is the longest and is slightly curved ; it commences above the anteroventral corner 
and slopes obliquely upwards towards the posterior ending in the posterior quarter. 
The ventral ridge is confined in the posterior part of the carapace and is intercalated 
between the ventral margin and the second ventral ridge, to which it is almost 
parallel. Anterodorsal furrow well-developed, delimited on the anterior by a short 
almost vertical ridge, and on the posterior by the anterior portion of the dorsal ridge. 
Anterior and posterior platforms almost smooth, compressed. Anterior marginal 
rim elevated, ventral and posterior marginal rims less high. Radial pore canals not 
detectable. Duplicature moderate. Selvage well-marked ; it is submarginal in left 
valve but in the outer third of the duplicature in right valve, which also has well- 
developed anterior and ventral flange grooves. Hinge holamphidont with stirpate 
anterior tooth in right valve. 

Dimensions (mm). 

L H w 

Io. 4314 Carapace male (holotype) o-68 0-37 0-34 

Io. 4262 Carapace female 0-59 0-37 0-34 

Comparison. A. rupina can easily be differentiated from other known species of 



FROM WEST PAKISTAN 17 

Alocopocythere by its anterodorsal groove, which is not only delimited by an anterior 
ridge but by a posterior ridge as well. 

Remarks. This is so far the oldest known species of the genus Alocopocythere. 
It occurs abundantly in one horizon (sample no. 31 11) of the Gorge Beds of the Rakhi 
Nala section, the male to female ratio being 1:3. 



Alocopocythere abstracta sp. nov. 
(Plate 3, figs. 5-11 ; Plate 4, fig. 1) 

Derivation of name. Latin abstr actus, separated, referring to the difficulty in 
separating this species from A. transcendens because of the many intermediate 
forms. 

Diagnosis. A reticulate Alocopocythere with straight postero-ventral margin in 
lateral outline. Subcentral-tubercle present but not prominent. 

Holotype. Io. 4312, a female carapace (PL 3, figs. 9-11) ; (PI. 4, fig. 1). 

Paratype. Io. 4263. 

Material. Over 2600 specimens (including adults and juveniles) from the Rakhi 
Nala section from 69 horizons (sample nos. 3147, 3152, 3153, 3157 to 3180, 3183, 
3184, 3186 to 3191, 3193 to 3194, 3197 to 3200, 3401 to 3405, 3407, 3409, 3410, 3415 
to 3424. 3426, 3428, 3429. 3432, 3434. 3435. 3438, 3443 and 3445). 5 specimens from 
the Zao River section from one horizon (sample no. 24127). GSP BM 2511-2512. 

Type locality. Rakhi Nala section. 

Type horizon. Upper Rakhi Gaj Shales, sample no. 3163. 

Description. Carapace subrectangular in side view. Sexual dimorphism rather 
pronounced ; the males are longer than the females. Dorsal margin sinuous, ventral 
margin nearly straight. Anterior margin broadly and evenly rounded, postero- 
dorsal margin very slightly concave ; posterior extremity rounded ; postero-ventral 
margin straight. Anterior and posterior cardinal angles protruding. Valves more 
or less equal. Eye-tubercle distinct. Subcentral-tubercle present but not pronounced. 
Surface reticulate. Anterodorsal furrow deep, bounded anteriorly by a short 
almost vertical ridge diagnostic of the genus. Anterior and posterior margins 
denticulate, although the denticles are only present in a few specimens. Internal 
details not known. 

Dimensions (mm). 

L H W 

Io. 4263 Carapace male o-66 0-38 0-34 

Io. 4312 Carapace female (holotype) 0-63 0-39 0-35 

Comparison. Alocopocythere coarctata sp. nov. is smaller than the present species 
and has a combination of reticulations and weak ridges and a more sinuous dorsal 
margin. Alocopocythere radiata sp. nov., however, is larger, has deeper reticulations 
and a better developed subcentral-tubercle having posterior radial ridges. 

A. abstracta has already been compared with Alocopocythere transcendens sp. nov. 



18 EARLY TERTIARY OSTRACODA 

Alocopocythere coarctata sp. nov. 

(Plate 4, figs. 2-9) 

Derivation of name. Latin coarctatus, " pressed together " ; with reference to 
the carapace. 

Diagnosis. Alocopocythere in which carapace in lateral outline appears to be 
compressed ; dorsal and ventral margins tapering towards the posterior end, sub- 
central-tubercle distinct, anterior marginal rim high, surface finely reticulate (with 
superimposed weak longitudinal ridges) . 

Holotype. Io. 4313, a female carapace (PI. 4, figs. 6-9). 

Paratype. Io. 4264. 

Material. 49 specimens from the below locality from five horizons (sample 
nos. 3432, 3434, 3435, 3458 and 3459) . GSP BM 2513-4. 

Type locality. Rakhi Nala section. 

Type horizon. Shales with Alabaster, sample no. 3458. 

Description. Carapace subrectangular to subquadrate in lateral view. Sexual 
dimorphism strong ; the females are shorter than the males. Anterior margin 
broadly and evenly rounded, posterodorsal margin straight, particularly in the left 
valve, posterior extremity rounded, posteroventral margin rounded. Dorsal margin 
sinuous with a hump between the protruding anterior and posterior cardinal angles, 
ventral margin slightly concave in the middle. Both dorsal and ventral margins 
taper towards the posterior. Valves almost equal. Surface finely reticulate with 
superimposed weak longitudinal ridges. Subcentral-tubercle distinct, eye-tubercle 
more or less distinct. Marginal rim present, elevated in the anterior, less elevated 
round the venter and posterior. Anterodorsal furrow fairly distinct and is bounded 
anteriorly by a short almost vertical ridge. Anterior and posterior margins denticu- 
late. Internal characters not known. 

Dimensions (mm). 

L 

Io. 4264 Carapace male 0-51 

Io. 4313 Carapace female (holotype) 0-50 

Comparison. Unlike A. coarctata, Alocopocythere rupina sp. nov. has better 

developed longitudinal ridges and coarser reticulation. In addition, these two 

species differ in lateral outline, particularly the male dimorphs. Alocopocythere 

transcendens , sp. nov. is larger, has a less well-developed hump between the protruding 

anterior and posterior cardinal angles and lacks longitudinal ridges. 

Alocopocythere longilinea sp. nov. 

(Plate 4, figs. 10-13 ; Plate 5, figs. 1-3, 6) 

Derivation of name. Latin longi, longitudinal + linea, line. 

Diagnosis. A small Alocopocythere in which surface ornamentation is reticulate, 



H 


W 


0-27 


0-27 


0-32 


0-29 



FROM WEST PAKISTAN 19 

the reticulae being arranged in longitudinal lines with weak ridges in between, 
subcentral-tubercle indistinct, marginal rim low, anterior marginal area compressed. 

Holotype. Io. 4318, a male carapace (PI. 4, figs. 10-13). 

Paratype. Io. 4265. 

Material. Nearly 670 specimens (including adults and juveniles) from the Rakhi 
Nala section from 10 horizons (sample nos. 3438, 3440, 3443 to 3445, 3448, 3450, 3451, 
3457 and 3458). One specimen from the Shpalai Khwara section from one horizon 
(sample no. 24683). GSP BM 2515-6. 

Type locality. Rakhi Nala section. 

Type horizon. Shales with Alabaster, sample no. 3443. 

Description. Carapace ovate in lateral outline and slightly tapering towards the 
posterior. Sexual dimorphism marked ; the males are longer in proportion than the 
females. Anterior margin broadly and obliquely rounded, somewhat compressed, 
posterior almost straight, posteroventral margin slightly curved. Dorsal margin 
sinuous, ventral margin evenly curved. Valves nearly equal. Subcentral-tubercle 
indistinct. Eye-tubercle low. Surface ornamentation consists of a combination of 
reticulations and weak ridges. Anterodorsal furrow deep with a short more or less 
vertical anterior ridge characteristic of the genus. Marginal rim low. Internal 
characters unknown. 

Dimensions (mm). 

L H w 

Io. 4318 Carapace male (holotype) 0-54 0-32 0-25 

Io. 4265 Carapace female 0-46 0-30 0-24 

Comparison. The present species differs from Alocopocy there abstracta sp. nov. 
and Alocopocythere transcendens sp. nov. in being smaller and having weak longitudinal 
ridges. Moreover, A. longilinea has a low marginal rim and an indistinct sub- 
central-tubercle. Alocopocythere coarctata sp. nov. is about the same size but has a 
high marginal rim, well-developed subcentral-tubercle and more sinuous dorsal 
margin. 

Remarks. A. longilinea occurs in the lower part of the Shales with Alabaster 
of the Rakhi Nala section and at several horizons it is very abundant. It is very rare 
in the Shpalai Khwara section. 

Alocopocythere transversa sp. nov. 
(Plate 5, figs. 4, 5, 7-10 ; Plates 6-8 ; Plate 9, figs. 1-5) 

Derivation of name. Latin transversus, transverse ; with reference to the 
posterior ridges. 

Diagnosis. A species of the genus Alocopocythere with three posterior transverse 
concentric ridges. A short ridge in the anteroventral area runs obliquely from the 
anterior towards the venter, a shallow groove on the dorsal side of the ridge. Surface 
reticulate (with or without superimposed papillae) or papillose. 

Holotype. Io. 4316, a female carapace (PL 5, figs. 8, 10) ; (PL 6, figs. 1, 2). 



20 



EARLY TERTIARY OSTRACODA 



Paratypes. Io. 4266-9 + lo. 3107-12. 

Material. Over 800 specimens from the Zao River section from 20 horizons 
(sample nos. 24131, 24155, 24157, 24159, 24170, 24173 to 24178, 24180, 24181, 24183 
to 24188 and 24195). Approximately 300 specimens from the Rakhi Nala section 
from 20 horizons (sample nos. 3624 to 3626, 3630, 3631, 3634, 3640 to 3642, 3645, 
3646, 3648 to 3653, 3658 and 3660). GSP BM 2157-8. 

Type locality. Zao River section. 

Type horizon. Upper Chocolate Clays, sample no. 24155. 

Description. Sexual dimorphism rather marked, the males are more elongate 
than the females. Carapace subrectangular in lateral view. Dorsal margin sinuous, 
ventral margin straight or evenly curved. Anterior margin broadly rounded, 
posterodorsal margin very slightly concave, posterior extremity rounded, postero- 
ventral margin rounded or almost straight. Anterior and posterior cardinal angles 
well-developed and protruding. Valves nearly equal. Eye-tubercle distinct, 
polished and rounded. Subcentral-tubercle distinct. Surface either reticulate (with 
or without superimposed papillae) or papillose. There are three posterior transverse 
concentric ridges approximately parallel to the posterior margin with grooves in 
between. There is a short ridge in the antero ventral area running obliquely from 
the anterior towards the venter, with a groove on the dorsal side. Anterodorsal 
groove fairly deep and bounded on the anterior by a short almost vertical ridge 
running from the eye-tubercle. The marginal rim is high in the anterior but less high 
on the venter and posterior. Anterior and posterior margins ornamented with short 
spines, only present in some specimens and approximately 20 anteriorly and 10 
posteriorly. Normal pore canals simple, small and numerous. Radial pore canals 
numerous, simple, nearly straight, some in groups of two or three, often apparently 
crossing one another. Duplicature moderately wide. Selvage pronounced in the 
outer third of the duplicature in the right valve but sub-marginal in the left valve. 
Right valve with deep ventral and anterior flange grooves. Line of concrescence and 
inner margin coincide. Muscle scars consist of four adductors in a vertical row with 
an oval frontal scar and two almost rounded mandibular scars below. Hinge 
holamphidont : 
Element 
Anterior 






Anteromedian 



Posteromedian 
Posterior 



Left valve 

Deep rounded socket 
bounded on all sides, 
confluent with ocular 
sinus. 

Subcorneal projecting 
tooth with a straight 
anterior and convex 
posterior in dorsal view. 
Denticulate bar 
Deep elongate socket 
unbounded on venter 



Right valve 

Strongly projecting stirpate 

tooth (ocular sinus situated 

below and slightly anterior 

to it). 

Deep socket. 



Locellate groove 
Pessular tooth with a 
tendency towards reniform, 
higher on posterior. 



FROM WEST PAKISTAN 21 

Comparison. Alocopocythere radiata sp. nov. is similar and perhaps related but 
lacks the posterior concentric ridges. Moreover, A. radiata has ventral inflation 
culminating in a ventral ridge and the longitudinal ridges radiate from the posterior 
of a subcentral-tubercle. 

The present species has already been compared with Alocopocythere transcendens 
sp. nov. 

Remarks. This species may be divided into the following morphotypes, which 
may represent the chronological subspecies of A. transversa. However, because of 
the difficulty in separating these from one another and also owing to the fact that the 
reticulate forms recur in the Upper Eocene succession of the Rakhi Nala and Zao 
River sections, these are here considered as morphotypes. 

Morphotype A 
(PI. 5, figs. 4, 5, 7-10 ; PL 6, figs. 1-4) 

This has a reticulate surface. The reticulae are usually without any super- 
imposed papillae but in some specimens a few small papillae at the junction of 
reticulae are present. The postero ventral margin in lateral outline is curved in the 
male but straight in the female. 

Dimensions (mm). 

L 
Io. 4266 Carapace male 0-76 

Io. 4316 Carapace female (holotype) 0-71 

Io. 3107 Right valve male 0-85 

Morphotype B 

This comprises the transitional forms which fall between Morphotype A and 
Morphotype C. It has slightly papillose reticulae. Specimens Io. 5004-5 from 
sample 24155. 

Morphotype C 
(Plate 6, figs. 5-8 ; Plate 7, figs. 1-4 ; Plate 8, fig. 4) 

This is similar to Morphotype B, but has a combination of reticulations and 
papillae and a curved postero ventral margin in both male and female. 

Dimensions (mm). 

L H W 

Io. 4267 Carapace male 0-78 0-46 0-44 

Io. 4268 Carapace female 0-76 0-46 0-44 

Io. 4269 Right valve male (broken) o-8o — — 

Morphotype D 

This includes the intermediate forms between Morphotype C and Morphotype E. 
Specimens Io. 5006-7 from sample 24175. 



H 


w 


0-44 

o-45 
0-46 


0-44 
0-44 



22 EARLY TERTIARY OSTRACODA 

MORPHOTYPE E 

(Plate 7, figs. 5-8 ; Plate 8, figs. 1-3, 5) 

This is similar in all characters to Morphotype A and Morphotype C but has a 
papillose surface. It has a curved posteroventral margin in the male and female 
dimorphs as in Morphotype C. There is a smooth, shallow groove on the dorsal side 
of the ventral ridge. 

Dimensions (mm). 

L H w 

Io. 3110 Carapace male o-8o 0-46 0-46 

Io. 3111 Carapace female 0-74 0-46 0*45 

Morphotype F 
(Plate 8, figs. 6-9 ; Plate 9, figs. 1-5) 

This has a small carapace. The surface is ornamented with slightly papillose 
reticulae. There is a rim behind the anterior marginal rim and almost parallel to it 
with reticulations in between. It originates from the eye-tubercle and fuses ventrally 
with a short, oblique ventral ridge. It is likely that these forms may be juveniles of 
Morphotype A or Morphotype C or may even belong to a distinct species. 

Dimensions (mm). 

L 
Io. 3109 Carapace male o-68 

Io. 3108 Carapace female 0-64 

Io. 3112 Right valve female 0-59 

Alocopocythere radiata sp. nov. 
(Plate 9, figs. 6-9 ; Plate 10, figs. 1-4) 

Derivation of name. Latin radiatus, rayed ; with reference to the ridges 
radiating from the subcentral-tubercle. 

Diagnosis. A coarsely reticulate Alocopocythere with longitudinal ridges radia- 
ting from the posterior of a well-developed subcentral-tubercle. Eye-tubercle 
distinct, marginal rim high, ventral inflation ends in a marked ridge, almost parallel 
to the ventral marginal rim. 

Holotype. Io. 4317, a male carapace (Plate 9, figs. 6, 8 ; Plate 10, figs. 1, 2) 

Paratype. Io. 4270. 

Material. 14 specimens from the locality below from one horizon (sample 
no. 3652). 8 specimens from the Zao River section from one horizon (sample no. 
24173). GSP BM 2519-20. 

Type locality. Rakhi Nala section. 

Type horizon. Upper Chocolate Clays, sample no. 3652. 

Description. Sexual dimorphism distinct ; the females are shorter than the 



H 


w 


o-39 


o-39 


o-39 


0-38 


o-37 


— 



H 


W 


0-42 


0-42 


042 


0-40 



FROM WEST PAKISTAN 23 

males. Carapace subrectangular in lateral view. Dorsal margin sinuous with 
protruding anterior and posterior cardinal angles ; ventral margin almost straight. 
Anterior margin broadly and evenly rounded, posterior extremity rounded, postero- 
dorsal margin very slightly concave, posteroventral margin curved in the male 
dimorph but almost straight in the female. Valves more or less equal. Eye- 
tubercle rounded and distinct. Surface ornamentation consists of coarse reticula- 
tions with superimposed ridges radiating from the posterior of a well-developed 
subcentral-tubercle. The ventral inflation culminates in a marked ventral ridge 
almost parallel to the ventral marginal rim. There are two ridges which join the 
eye-tubercle, one a short more or less vertical ridge bounded posteriorly by a deep 
anterodorsal furrow which is better seen in dorsal view, and the other a high anterior 
marginal rim which continues along the venter and around the posterior as a less high 
rim. Anterior and posterior margins decorated with numerous very short and 
delicate spines. 

Dimensions (mm). 

L 
Io. 4317 Carapace male (holotype) 0-72 

Io. 4270 Carapace female 0-68 

Comparison. Alocopocythere transcendens sp. nov. shows some resemblance and 
is perhaps ancestral to the present species ; but A. transcendens has a less well- 
developed subcentral-tubercle without radial ridges and lacks a ventral inflation 
ending in a ridge. Alocopocythere coarctata sp. nov. is much smaller, has a carapace 
which tapers towards the posterior end and has a less deep surface reticulation. 



Genus " ANOMMATOCYTHERE " Sohn 

Type species. " Anommatocythere microreticulata " Sohn. 

Remarks. This is a new genus erected by Sohn whose paper is in press. The 
two species described below are provisionally assigned to the genus but their final 
designation will depend on the publication of Sohn's paper. 

" Anommatocythere " laqueata sp. nov. 
(Plate 10, figs. 5-10) 

Derivation of name. Latin laqueatus, fluted ; with reference to the ornamenta- 
tion of the anterior rim. 

Diagnosis. Anterior rim ornamented with seven small more or less rectangular 
depressions. Carapace subtriangular with a gently convex dorsal margin. 

Holotype. Io. 4320, a female carapace (Plate 10, figs. 8-10). 

Paratype. Io. 4271. 

Material. 32 specimens from the locality below from three horizons (sample 
nos. 3403, 3405 and 3466). Two specimens from the Zao River section from one 
horizon (sample no. 24107). GSP BM 2521-2. 



H 


W 


o-37 


0-32 


o-39 


o-34 



24 EARLY TERTIARY OSTRACODA 

Type locality. Rakhi Nala section. 

Type horizon. Green and Nodular Shales, sample no. 3403. 

Description. Sexual dimorphy rather apparent ; the males are longer in pro- 
portion than the females. Carapace subtriangular in lateral view. Dorsal margin 
gently convex, ventral margin almost straight, anterior margin broadly rounded, 
posterior with a caudal process. Greatest length lies below mid-point, greatest 
height at anterior cardinal angle. Anterior and posterior cardinal angles more or 
less rounded, somewhat better developed in the left valve. Left valve very slightly 
larger than the right valve, over-reaching it in the anterodorsal corner and postero- 
dorsal slope. Siibcentral-tubercle indistinct. Eye-tubercle distinct but low. Surface 
reticulate, the reticulae being arranged in lines separated by longitudinal ribs. 
Anterior marginal rim ornamented with seven small rectangular depressions like a 
scallop or bivalve mollusc. Internal characters not observed. 

Dimensions (mm). 

L 
Io. 4271 Carapace male 0-66 

Io. 4320 Carapace female (holotype) 0-66 

Comparison. " Anommatocy there " confirmata sp. nov. differs from the present 
species by having a thick-shelled and ventrally inflated carapace, a convex rather 
than straight ventral margin in lateral view, and no ornamentation of the anterior 
rim. 

Remarks. Specimens from the Shales with Alabaster show fainter longitudinal 
ribs. This is perhaps due to the form of preservation. 

" Anommatocythere " confirmata sp. nov. 
(Plate io, figs. 11, 12 ; Plate n ; Plate 12, figs. 1, 2) 

Derivation of name. Latin confirmatus, " strengthened " ; with reference to 
the variation in the strength of the longitudinal ribs. 

Diagnosis. Carapace ventrally inflated and with a short caudal process. Ventral 
longitudinal ribs are curved and better developed. Anterior and posterior cardinal 
angles well-marked. 

Holotype. Io. 4319, a male carapace (PL 10, figs. 11, 12) ; (PI. n, figs. 1, 2) 

Paratype. Io. 4272 + Io. 3102-3. 

Material. 70 specimens from the Rakhi Nala section from five horizons (sample 
nos. 3499, 3611, 3613-3615). 53 specimens from the Zao River section from six 
horizons (sample nos. 24145, 24147, 24148, 24150 to 24152). GSP BM 2523-4. 

Type locality. Rakhi Nala section. 

Type horizon. Upper Chocolate Clays, sample no. 3611. 

Description. Sexual dimorphism rather marked, the females are shorter and 
wider in proportion than the males. Carapace plump, thick-shelled and with ventral 
inflation. Dorsal margin slightly convex particularly in the right valve, ventral 



FROM WEST PAKISTAN 



25 



margin anteromedially concave but is convex in lateral outline due to the ventral 
inflation ; anterior margin broadly rounded, posterior with a short caudal process. 
Anterior and posterior cardinal angles well-developed particularly in the left valve. 
Left valve slightly over-reaches the right at the anterodorsal and posterodorsal 
corners. Subcentral-tubercle present but not distinct. Eye-tubercle rounded, shiny 
and distinct and lies below and slightly anterior to cardinal angle. Surface ornamen- 
tation consists of reticulations and longitudinal ribs. There is a variation in the 
strength of the longitudinal ribs, those on the ventral surface are stronger and curved 
convexly downwards in the middle. Marginal rim narrow and low. Anterior and 
posterior margins denticulate. Valves deep in internal view. Normal pore canals 
fairly numerous and perhaps each reticule has one normal pore canal. Radial pore 
canals simple, straight, sparse, irregularly spaced, few crossing one another, approxi- 
mately 20 anteriorly and 8 posteriorly. Line of concrescence and inner margin 
coincide — no vestibule. Duplicative fairly wide — 0-073 mm. anteriorly, 0-055 mm - on 
the posterior extremity. Selvage distinct and subperipheral ; situated in the right 
valve on the outer sixth of the anterior margin. Right valve with a ventral flange 
groove between selvage and flange. Muscle scar pattern with four adductor scars in 
an almost vertical superposition at the posterior margin of the muscle scar pit and 
two more or less rounded frontal scars. Hinge holamphidont with the following 
details of the hinge elements : 



Element 
Anterior 



Anteromedian 



Posteromedian 



Posterior 



Dimensions (mm). 



Left valve 

Deep socket bounded 
on all sides, eye- 
socket lies almost in 
the middle of it. 
Conical tooth, 
projecting slightly 
towards anterior. 
Denticulate bar 



Deep and elongate 
socket unbounded on 
ventral side. 



Right valve 
Strongly projecting 
stirpate tooth. 



Deep socket narrowing 

posteriorly into a long 

groove. 

Locellate groove, the 

anterior part deeper than 

posterior. 

Large bilobate tooth, the 

anterior lobe lower than 

the posterior. 



Io. 4319 Carapace male (holotype) 

Io. 4272 Carapace female 

Io. 3102 Left valve male 

Io. 3103 Right valve male 

Comparison. This species has already been compared with " Anommatocythere 
laqueata sp. nov. 



L 


H 


w 


o-66 


o-39 


o-39 


0-63 


0-42 


0-44 


0-64 


o-39 


— 


0-63 


o-37 


— 



Remarks. The vertical range of the present species in the Rakhi Nala and Zao 



26 EARLY TERTIARY OSTRACODA 

River sections is 286 ft. and 378 ft. respectively. Hence, it is a very useful species 
as a horizon marker in the region. 

Adult specimens in the two sections vary in size and in the strength of 
ornamentation. 



Genus BRADLEY A Hornibrook 1952 
Type species. Cythere arata Brady 1880. 

Bradleya ? voraginosa sp. nov. 
(Plate 12, figs. 3-9) 

Derivation of name. Latin voraginostis, full of pits. 

Diagnosis. A species provisionally placed in the genus Bradleya with sub- 
parallel dorsal and ventral margins, projecting anterior cardinal angle, truncated 
posterior, coarsely and deeply reticulate surface. 

Holotype. Io. 4321, a male carapace (PI. 12, figs. 3, 5, 7, 8). 

Paratype. Io. 3115. 

Material, io specimens from the locality below from two horizons (sample 
nos. 24159 and 24161). GSP BM 2525. 

Type locality. Zao River section. 

Type horizon. Upper Chocolate Clays, sample no. 24161. 

Description. Carapace subrectangular in lateral outline. Valves ventrally 
inflated. Dorsal and ventral margins almost straight and subparallel, anterior 
margin broadly rounded, posterior truncated, posterodorsal slope very slightly 
concave particularly in the right valve. Anterior cardinal angle projecting, posterior 
cardinal angle rather prominent (approximately 110°). Valves almost equal. Eye- 
tubercle rounded and distinct and situated just below the anterior cardinal angle. 
Subcentral-tubercle more or less distinct. A marginal rim runs around the anterior, 
ventral and posterior margins. It is fairly well-developed anteriorly and posteriorly 
but is not so prominent along the venter. Surface ornamentation consists of 
coarse, deep reticulations and dorsal and ventral ridges. 

The dorsal ridge is ill-defined in the anterior half, slightly arched upward in the 
posterior third culminating in a short horn-like posterodorsal process. The ventral 
ridge is better developed and slightly alate posteriorly. Anterior margin finely 
denticulate, posteroventral margin ornamented with 4-5 short spines. Internal 
details not very well displayed. Duplicature fairly wide. Selvage in the left valve 
is subperipheral and less well-developed than in the right valve where it is at some 
distance from the outer margin. It has a deep flange groove, particularly in the 
venter. Hinge holamphidont ; left valve with a deep almost rounded anterior 
socket which is bounded on all sides, a conical projecting anteromedian tooth, an 
apparently denticulate bar and a deep elongate posterior socket which is bounded 
on the venter. Hinge of right valve not clearly seen. 



H 


W 


0-42 


0-42 


0-40 


0-42 



FROM WEST PAKISTAN 27 

Dimensions (mm). 

L 
Io. 4321 Carapace male (holotype) 076 

Io. 3115 Carapace female 0-73 

Comparison. Bradley a ? cornuelina (Bosquet) Keij (1957) is similar to B ? 
voraginosa in lateral view but has three rather than two longitudinal ridges. Further, 
it has a less well-developed anterior cardinal angle. Bradleya approximata (Bosquet) 
Keij (1957) has a different posterior and larger posteroventral spines. 



Genus BUNTONIA Howe 1935 
Type species. Buntonia shubutaensis Howe 1935. 

Buntonia devexa sp. nov. 

(Plate 13, figs. 1-5) 

Derivation of name. Latin devexus, sloping ; with reference to the tapering 
lateral outline. 

Diagnosis. A species of Buntonia in which carapace is elongate, subrectangular 
in lateral view ; surface ornamented with 9-1 1 longitudinal ribs in posterior three- 
fifths of carapace. 

Holotype. Io. 4322, a female carapace (PI. 13, figs. 2, 4, 5). 

Paratype. Io. 3113. 

Material. 8 specimens from the locality and horizon below. 

Type locality. Rakhi Nala section. 

Type horizon. Gorge Beds, sample no. 3111. 

Description. Sexual dimorphism rather pronounced ; the males are longer and 
less wide than the females. Carapace sub-triangular in lateral view, tapering 
towards the posterior. Anterior margin broadly and obliquely rounded, posterior 
narrowly rounded, dorsal and ventral margins almost straight, dorsal margin slopes 
downwards towards posterior. Greatest length passes through the midpoint, 
greatest height in the anterior third and greatest width in the posterior two-fifths. 
Anterior cardinal angle rounded. Left valve slightly larger than the right valve. 
Surface ornamentation consists of 9-1 1 longitudinal ridges, which are more or less 
confined in the posterior three-fifths. Anterior marginal rim distinct. 

Dimensions (mm). 

L H w 

Io. 3113 Carapace male o-8o 0-39 0-24 

Io. 4322 Carapace female (holotype) 073 0-35 0-27 

Comparison. Buntonia virgulata Apostolescu (1961) has punctae between 
longitudinal ridges and a less elongate carapace. Cythere cf. costellata (Roemer) 
Latham (1938) is similar and may even be conspecific. However, her figure, which 



28 EARLY TERTIARY OSTRACODA 

appears to be drawn upside down, shows longitudinal ridges continuing in the 
anterior part of the carapace. 

Remarks. Cythere costellata (Roemer) is now regarded as a species of the genus 
Cytheretta. Because of the imperfect preservation, it has not been possible to observe 
whether the present species has any eye-tubercles. 

Buntonia Sp.A 
(Plate 13, figs. 6, 7, 9) 

Figured specimen. Io. 3114. 

Material. Two specimens from the locality and horizon below. 

Locality. Rakhi Nala section. 

Horizon. Lower Rakhi Gaj Shales, sample no. 3133. 

Description. Carapace small, almost triangular in lateral outline. Greatest 
length lies below mid-point, greatest height in anterior third. In dorsal view the 
carapace is widest just posterior to the middle and tapers towards anterior and 
posterior ends ; posterior pointed. Anterior end broadly and obliquely rounded, 
posterior narrow and somewhat rounded ; dorsal and ventral margins taper towards 
the posterior. Anterior cardinal angle rounded and well-developed. Left valve 
larger than right valve. Surface ornamented with some ten longitudinal ridges. 

Dimensions (mm). 

L H w 

Io. 3114 Carapace 0-50 0-27 0-32 

Comparison. Buntonia devexa sp. nov. (PI 13, figs. 1-5) is much larger, has a less 
triangular carapace with a gentle slope on the dorsal margin. Further, B. devexa has 
a rounded rather than pointed posterior in dorsal view and has longitudinal ridges 
which do not continue towards the anterior. 

Genus COSTA Neviani 1928 

Diagnosis. Trachyleberididae in which ornamentation is dominated by three or 
four longitudinal ridges, the median or second ridge running back from the sub- 
central-tubercle towards posterodorsal corner in anterior two-thirds of length, then 
curving sharply down towards posteroventral corner in posterior third of length. 

Type species. Cytherina edwardsii Roemer 1838. 

Subgenus COSTA sensu stricto 
Diagnosis. Costa with three longitudinal ridges. 

Subgenus PARACOSTA nov. 

Derivation of name. Greek para, near ; with reference to the strong resem- 
blance to the subgenus Costa. 



FROM WEST PAKISTAN 29 

Diagnosis. Costa with a fourth ventral ridge intercalated between third ridge 
and ventral margin. 

Type species. Costa (Paracosta) declivis sp. nov. 

Remarks. The subgenus Paracosta is so far only known from the Rakhi Nala 
section. It is represented by two species in the Upper Chocolate Clays and one 
species in the Pellatispira Beds. 

Costa (Paracosta) declivis sp. nov. 

(Plate 13, figs. 8, 10-14 ; Plate 14, figs. 1, 2) 

Derivation of name. Latin declivis, sloping downward ; referring to the 
direction of the ridge running anteroventrally from the subcentral-tubercle. 

Diagnosis. A small species of Paracosta in which longitudinal ridges are well- 
developed, median or second ridge runs anteroventrally from subcentral-tubercle. 

Holotype. Io. 4325, a male carapace (pi. 13, figs. 8, 10-12). 

Paratypes. Io. 4273 — Io. 3116. 

Material. 34 specimens from the Rakhi Nala section from four horizons (sample 
nos. 3661 to 3664) . GSP BM 2526-7. 

Type locality. Rakhi Nala section. 

Type horizon. Pellatispira Beds, sample no. 3662. 

Description. Sexual dimorphism marked, the males are longer than the females. 
Carapace elongate, subrectangular in lateral view with greatest height at anterior 
cardinal angle. Dorsal and ventral margins almost straight, subparallel, anterior 
end broadly rounded, posterior subtriangular. Valves almost equal. Anterior 
cardinal angle rounded, posterior cardinal angle obtuse. Greatest width in the 
posterior third. Subcentral-tubercle distinct. Eye-tubercle rounded and distinct. 
Ornamentation consists of reticulations dominated by four longitudinal ridges. 
The dorsal ridge commences just above the subcentral-tubercle and is slightly 
arched upward (in lateral view over-reaching dorsal margin), the median or second 
ridge runs almost diagonally from anteroventral margin towards posterodorsal 
corner, then bending down towards posteroventral margin ; the ventral or fourth 
ridge (better seen in ventral view) lies between the third ridge and the ventral 
margin and is not as well-developed as the other three. Anterior and posterior 
marginal rims high. Anterior margin ornamented with 15-18 small spines, postero- 
ventral margin with 5-6 relatively large spines. Internal characters unknown. 

Dimensions (mm). 

L 
Io. 4325 Carapace male (holotype) 0-83 

Io. 4273 Carapace female 0-77 

Io. 3116 Carapace female 077 

Comparison. This species differs from Costa {Paracosta) disintegrata sp. nov. in 
having well-developed longitudinal ridges and a different outline. Costa {Paracosta) 



H 


w 


o-39 


o-37 


o-39 


o-37 


o-39 


o-37 



30 EARLY TERTIARY OSTRACODA 

compitalis sp. nov. is larger, lacks well-developed longitudinal ridges and has a ridge 
running from the eye-tubercle to the subcentral-tubercle. 

Costa (Paracosta) compitalis sp. nov. 

(Plate 14, figs. 3-10) 

Derivation of name. Latin compitalis, pertaining to a cross-roads ; referring 
to the nexus of the ridges running from the subcentral-tubercle. 

Diagnosis. A large, strongly reticulate species of the subgenus Paracosta in 
which longitudinal ridges are moderately developed, subcentral-tubercle prominent, 
joined by three ridges — dorsal, median and a ridge running from eye-tubercle. 

Holotype. Io. 4323, a female carapace (PI. 14, figs. 5, 6, 9, 10). 

Paratype. Io. 4274. 

Material. 14 specimens from the locality below from one horizon (sample 
no. 3604) . GSP BM 2528-9. 

Type locality. Rakhi Nala section. 

Type Horizon. Upper Chocolate Clays, sample no. 3604. 

Description. Carapace subrectangular in lateral outline. Sexual dimorphism 
rather pronounced ; the females are shorter and higher than the males. Dorsal 
margin slightly curved in lateral view because of over-reaching by the dorsal ridge ; 
ventral margin straight, anterior broadly and evenly rounded, posterodorsal margin 
very slightly concave, posterior extremity slightly subtriangular, posteroventral 
margin rounded. Greatest height at anterior cardinal angle, greatest length 
through the mid-point and greatest width in posterior third. Anterior cardinal 
angle well-developed with a concavity behind. Left valve slightly larger than right 
valve, over-reaching at posterodorsal margin and in the region of anterior cardinal 
angle. Eye-tubercle rounded and distinct and confluent with the anterior marginal 
rim and a ridge running from the subcentral-tubercle. The prominent subcentral- 
tubercle lies more or less in the anterior third. Surface coarsely reticulate. There 
are four longitudinal ridges ; the dorsal ridge commences at the subcentral-tubercle 
and is curved convexly upward, the median or second ridge stretches back from the 
subcentral-tubercle towards posteroventral margin, the third ridge slightly slopes 
upward towards the posterior end and the ventral ridge is almost parallel to the 
ventral margin and is intercalated between the third ridge and the ventral margin. 
Anterior and posterior marginal rims distinct. Anterior and posterior margins 
ornamented with numerous small spines. Internal details not known. 

Dimensions (mm). 

L H w 

Io. 4274 Carapace male 0-98 0-51 0-46 

Io. 4323 Carapace female (holotype) 0-93 0-51 0-44 

Comparison. Costa (Paracosta) disintegrata sp. nov. is smaller than the present 
species, has ill-defined longitudinal ridges and a carapace tapering towards the 
posterior end. 



FROM WEST PAKISTAN 31 

Costa (Paracosta) disintegrata sp. nov. 

(Plate 14, figs. 11 ; Plate 15, figs. 1-6) 

Derivation of name. Latin disintegratus, " broken down " ; referring to the 
relict nature of the ridges characteristic of Costa. 

Diagnosis. Paracosta of medium size with weakly developed longitudinal ridges. 
Carapace tapering towards posterior end in lateral view. 

Holotype. Io. 4324, a male carapace (PL 14, figs. 11 ; PL 15, figs. 3, 4). 

Paratype. Io. 4275. 

Material. Four specimens from the locality below from two horizons (samples 
no. 3621 and 3622). GSPBM 2530-31. 

Type locality. Rakhi Nala section. 

Type horizon. Upper Chocolate Clays, sample no. 3622. 

Description. Sexual dimorphy moderate ; the males are longer in proportion 
than females. Carapace subrectangular, tapering to posterior in side view. Dorsal 
and ventral margins almost straight, anterior margin broadly and evenly rounded, 
posterior subtriangular. Anterior cardinal angle rounded, posterior cardinal angle 
obtuse — well-developed in left valve. Left valve over-reaches the right slightly at 
the anterior cardinal angle and in the region of the posterodorsal slope. A distinct 
eye-tubercle lies just below the anterior cardinal angle. Subcentral-tubercle well- 
developed. Anterior and posterior marginal rims high. Surface coarsely reticulate 
(some reticulae being slightly papillose). There are four ill-defined longitudinal 
ridges ; the dorsal ridge commences just behind the subcentral tubercle and is curved 
convexly upward ; the second ridge stretching back from the subcentral-tubercle 
towards the posterodorsal corner in the anterior two-thirds and then bends sharply 
round towards the posteroventral corner ; the third ridge commences below the 
subcentral-tubercle and slopes upward towards the posterior end ; the fourth ridge 
(better seen in ventral view) is more or less parallel to the third ridge and lies between 
the ventral margin and the third ridge. Anterior and posterior margins spinose. 

Dimensions (mm). 

L H W 

Io. 4275 Carapace male 0-83 0-42 0-32 

Io. 4324 Carapace female (holotype) 0-85 0-44 0-37 

Comparison. This species falls between Costa (Paracosta) compitalis sp. nov. and 
Costa (Paracosta) declivis sp. nov. in size and stratigraphical position and has already 
been compared with these species. 



Genus ECHINOCYTHEREIS Puri 1954 

Diagnosis. Trachyleberididae with or without ventral ridges. Carapace often 
inflated and with curved posteroventral margin, particularly in right valve. Surface 
ornamented with papillae, nodes, reticulations (or combination of these — con- 



32 EARLY TERTIARY OSTRACODA 

centrically arranged in some species) or almost smooth. Muscle scars are in a 
vertical column of four adductors with two frontal scars. 

Type species. Cythereis garetti Howe and McGuirt 1935. 

Subgenus ECHINOCYTHEREIS sensu stricto 
Diagnosis. Echinocythereis without ventral ridges. 

Echinocythereis (Echinocythereis) contexta sp. nov. 
(Plate 15, figs. 7, 8, 10, 13) 

Derivation of name. Latin contextus, joined together ; from the ornamentation 
of the papillae joined by the walls of the reticulae. 

Diagnosis. A species of the subgenus Echinocythereis in which posterior end is 
obliquely rounded towards posterodorsal corner, eye-tubercle prominent, surface 
reticulate with superimposed papillae. 

Holotype. Io. 4326, a female carapace (PI. 15, figs. 8, 13). 

Paratype. Io. 4276. 

Material. Five specimens from the Sor Range section from four horizons 
(sample nos. 460-f, 460-i, 460-j and 460-0). GSP BM 2532-3. 

Type locality. Sor Range section. 

Type horizon. Upper Palaeocene, sample no. 460-i. 

Description. Sexual dimorphism rather strong ; the carapace is subrectangular in 
the male and subquadrate in the female. Dorsal margin in lateral outline un- 
dulating because of ornamentation, ventral margin almost straight, anterior broadly 
and evenly rounded. Greatest length passes above the mid-point, greatest height 
in the anterior fourth and greatest width behind the middle. Anterior and posterior 
cardinal angles well-developed. Left valve larger than the right, over-reaching 
it at the anterior, ventral and posterodorsal margins. Eye-tubercle rounded and 
prominent, standing out from the shell surface in lateral and dorsal views. Sub- 
central-tubercle more or less distinct. Surface ornamentation consists of slightly 
papillose reticulae which are concentrically arranged near the margins. Anterior 
and posterior margins are set with a double row of papillae ; those on the posterior 
are larger, and in some specimens become short spines. Internal details not seen. 

Dimensions (mm). 

L 
Io. 4276 Carapace male 0-78 

Io. 4326 Carapace female (holotype) 071 

Comparison. Unlike E. (E.) contexta sp. nov. Echinocythereis (Scelidocythereis) 
sp.A has a straight rather than curved posterodorsal margin and less prominent 
eye-tubercles. Moreover, it has a weak ventral ridge and a short horn-like postero- 
dorsal process. Echinocythereis (Echinocythereis) elongata sp. nov. also differs by 
possessing a very elongate carapace and a better developed subcentral-tubercle. 



H 


w 


0-44 


o-37 


0-46 


0-42 



FROM WEST PAKISTAN 33 

Echinocythereis (Echinocythereis) elongata sp. nov. 
(Plate 15, figs. 9, u, 12, 14 ; Plate 16, figs, i, 2) 

Derivation of name. Latin elongatus, elongate ; with reference to the carapace. 

Diagnosis. An elongate species of the subgenus Echinocythereis in which posterior 
end is rounded towards posterodorsal corner, subcentral-tubercle distinct, surface 
ornamented with reticulae and papillae. 

Holotype. Io. 4327, a female carapace (PL 15, figs. 12, 14 ; PL 16. fig. 1). 

Paratype. Io. 3130. 

Material. Nine specimens from the Rakhi Nala section from three horizons 
(sample nos. 3404, 3409 and 3416). GSP BM 2534. 

Type locality. Rakhi Nala section. 

Type horizon. Rubbly Limestones, sample no. 3416. 

Description. Carapace elongate, subrectangular in lateral outline. Sexual 
dimorphism rather prominent in dorsal view ; males longer and less wide than females. 
Anterior margin broadly rounded, posterior narrowly rounded towards postero- 
dorsal corner particularly in the left valve, dorsal margin irregular due to ornamenta- 
tion, ventral margin more or less straight. Greatest length lies above the middle, 
greatest height at the anterior cardinal angle and greatest width in front of the 
middle. Valves almost equal. Subcentral-tubercle distinct. Eye-tubercle fairly 
distinct, but worn in some specimens. Surface ornamentation a combination of 
reticulations and papillae. The reticulae are in the anterior and ventral regions and 
the papillae in the middle and posterior. The papillae are perhaps revealed by the 
removal of an upper layer of reticulae. The decorated papillae show normal pore 
canals and nexus of reticulae, which are smaller than the anterior and ventral ones. 
Normal pore canals are situated between the papillae. Anterior and posterior 
margins denticulate, although the denticles are not preserved in some specimens. 
Internal characters unknown. 

Dimensions (mm). 

L H W 

Io. 3130 Carapace male 0-73 0-39 0-29 

Io. 4327 Carapace female (holotype) 0-71 0-38 0-34 

Comparison. This species can easily be separated from the other known species 
of the subgenus Echinocythereis by its much more elongate carapace-. 



Subgenus SCELIDOCYTHEREIS nov. 

Derivation of name. Greek skelis, rib ; with reference to the development of 
the ventral ridges. 

Diagnosis. Echinocythereis with ventral ridges. 

c 



34 EARLY TERTIARY OSTRACODA 

Type species. Echinocythereis (Scelidocythereis) multibullata. sp. nov. 

Echinocythereis (Scelidocythereis) multibullata sp. nov. 
(Plate 16, figs. 3-9 ; Plate 17, figs. 1, 2, 7) 

Derivation of name. Latin multus, much + bullatus, knobbed ; with reference 
to the ornamentation. 

Diagnosis. A species of the subgenus Scelidocythereis with a prominent sub- 
central-tubercle consisting of 4-5 small nodes. Surface nodose or tuberculate. 
Right valve over-reaches left valve anteriorly but is over-reached by the latter at 
anterior and posterior cardinal angles. 

Holotype. Io. 4328, a male carapace (PI. 16, figs. 3, 5, 6 ; PI. 17, fig. 7). 

Paratypes. GSP BM 2558-I0. 3133-4 + Io. 4277. 

Material. 76 specimens from the Zao River section from five horizons (sample 
nos. 24154, 24156, 24159, 21461 and 24183). 28 specimens from the Rakhi Nala 
section from three horizons (sample nos. 3621, 2624 and 2625). GSP BM 2535-6. 

Type locality. Zao River section. 

Type horizon. Upper Chocolate Clays, sample no. 24161. 

Description. Sexual dimorphism rather marked ; presumed females shorter, 
higher and wider than presumed males. Carapace subrectangular in lateral view. 
Anterior margin broadly and evenly rounded in both valves. In the right valve the 
posterodorsal corner is very slightly concave, whilst the posterior extremity and the 
posteroventral margins are rounded ; in the left valve the posterior end is truncated. 
Dorsal margin intricate in lateral view because of ornamentation ; ventral margin 
slightly incurved anterior to the middle in the right valve but curved convexly down- 
ward in the left valve. Greatest length passes through the middle, greatest height 
at the anterior cardinal angle and greatest width in front of the middle (i.e. at the 
subcentral-tubercle). Anterior cardinal angle protruding. Right valve over- 
reaches the left at the anterior margin and posteroventral margin ; but left valve 
over-reaches the right in the region of the anterior and posterior cardinal angle. 
Subcentral-tubercle prominent and is composed of 4-5 small nodes. Eye-tubercle 
rounded and distinct. Surface ornamented with nodes, or tubercles, those nearest 
the ventral margin being the larger. There are three small ventral ridges, the two 
near the ventral margin are smaller and almost confined to the anteroventral and 
mid-ventral regions. Anterior and posterior margins are denticulate. Viewed 
internally the valves are deep. Duplicature fairly wide, o-n mm. at the posterior 
extremity (PI. 16, fig. 9). Selvage well-developed, subperipheral in the left valve but 
almost at the outer third in the right valve. A deep flange groove, better developed 
at the venter, lies between the selvage and flange in the right valve. Radial pore 
canals fairly numerous, simple, almost straight, few occurring in groups of two or 
three. Inner margin and line of concrescence coincide. Muscle scars (best seen in 
weathered specimens from the outside) are in an almost vertical column of four 
adductors and two more or less rounded frontal scars. Hinge holamphidont : 



FROM WEST PAKISTAN 



35 



Element 
Anterior 



Anteromedian 



Posteromedian 



Posterior 



Dimensions (mm) 



Left valve 

Deep, almost rounded 
socket bounded on all 
sides. 

Projecting subcorneal 
tooth. 

Slightly projecting 
denticulate ridge (den- 
ticles are seen only in 
nicely preserved 
specimens) . 
Deep elongate socket 
unbounded on venter. 



Right valve 
Highly projecting 
pessular tooth. 

Socket opening into 
posteromedian groove. 
Locellate groove. 



Large subpessular tooth, 
less high on anterior. 



Io. 4328 Carapace male (holotype) 

Io. 3134 Carapace female 

I°- 3 I 33 Left valve female 

Io. 4277 Right valve female 



L 
0-85 
0-83 
0-84 
0-83 



H 
0-50 

0-51 

o-54 
0-50 



w 

o-45 

0-48 



Comparison. Echinocythereis (Scelidocythereis) sparsa sp. nov. is smaller than the 
present species, has a different lateral outline, distinct marginal rims and scattered 
tubercles as surface ornamentation. In addition to this, it has an indistinct rather 
than prominent subcentral-tubercle. 

Remarks. This species occurs in the Upper Chocolate Clays of the Zao River and 
Rakhi Nala sections. It has a short vertical range and hence can be used as an index 
marker. 

Echinocythereis (Scelidocythereis) sp.A 
(Plate 17, figs. 3, 4, 8, 9) 

Figured specimen. Io. 3129. 

Material. Two specimens from the locality and horizon below. 

Locality. Sor Range section. 

Horizon. Upper Palaeocene, sample no. 460-i. 

Description. Carapace short, subquadrate in lateral view. Dorsal margin 
slightly irregular due to surface ornamentation, ventral margin almost straight, 
anterior broadly and evenly rounded, posterodorsal margin straight, posterior 
extremity somewhat rounded, posteroventral margin curved. Greatest length lies 
below mid-point, greatest height in the anterior third and greatest width behind the 
middle. Anterior and posterior cardinal angles well-developed. Valves almost 
equal. Eye-tubercle rounded, polished and distinct. Subcentral-tubercle present but 
not well-developed. Surface reticulate with superimposed papillae. A weak ventral 
ridge at some distance from the ventral margin slopes obliquely upwards towards the 



36 EARLY TERTIARY OSTRACODA 

posterior end. The posterodorsal process is a short horn-like ridge slightly anterior 
to the posterior cardinal angle. A marginal rim runs along anterior, venter and 
posterior margins. 

Dimensions (mm). 

L H W 

Io. 3129 Carapace 0-59 0-39 0-34 

Comparison. This species has already been compared with Echinocythereis 
(Echinocythereis) contexta sp. nov. 



Echinocythereis (Scelidocythereis) rasilis sp. nov. 
(Plate 17, figs. 5, 6, 10 ; Plate 18, figs. 1-3, 5, 7) 

Derivation of name. Latin rasilis, smoothed ; with reference to the carapace. 

Diagnosis. Carapace subreniform. Dorsal margin arched with a slight con- 
cavity behind the protruding anterior cardinal angle. Surface smooth with two 
ventral ridges. 

Holotype. Io. 4329, a female carapace (PI. 17, figs. 6 ; PI. 18, figs. 2, 3). 

Paratypes. Io. 4278 + Io. 3131-2. 

Material. 17 specimens from the Rakhi Nala section from three horizons 
(sample nos. 3499, 3614 and 3617). 41 specimens from the Zao River section from 
seven horizons (sample nos. 24145, 24147, 24148, 24150, 24152 and 24157). GSP 
BM 2537-8. 

Type locality. Rakhi Nala section. 

Type horizon. Lower Chocolate Clays, sample no. 3499. 

Description. Carapace subreniform in lateral outline, with the greatest height 
at the anterior cardinal angle. Dorsal margin arched with a slight concavity behind 
the anterior cardinal angle, ventral margin incurved anterior of the middle, particu- 
larly in the right valve ; anterior margin broadly rounded, posterodorsal slope very 
slightly concave, posterior extremity rounded, posteroventral margin curved or 
straight. In dorsal view the greatest width lies almost at the middle. Anterior and 
posterior marginal areas compressed. Anterior cardinal angle protruding, Right 
valve over-reaches left valve along the anterior and posteroventral margins. Left 
valve over-reaches right valve slightly in the regions of the anterior cardinal angle 
and posterodorsal slope. Surface smooth. There are two ventral ridges, the one 
nearest the ventral margin being smaller. Eye-tubercle more or less distinct and situ- 
ated below the anterior cardinal angle. Anterior margin finely denticulate (20-25 
small denticles), posterior with 6-8 larger denticles. Duplicature fairly wide, 
0-073 mm. anteriorly. In the right valve the selvage and flange groove are well- 
developed particularly in the anteroventral and ventral regions. In the left valve 
the selvage is well-marked but the flange groove is somewhat less well-developed. 
Radial pore canals not clearly visible but would seem to be simple, straight and 
numerous. No vestibule. Hinge not determinable. 



H 


w 


0-46 


o-37 


o-45 


o-37 


0-49 


o-37 


0-49 


0-42 



FROM WEST PAKISTAN 37 

Dimensions (mm). 

L 
Io. 4278 Carapace male 0-59 

Io. 4329 Carapace female (holotype) 0-56 

Io. 3131 Carapace male 076 

Io. 3132 Carapace female 0-78 

Comparison. Hemicythere sahnii Tewari and Tandon (i960) appears to be a 
closely related species. Specimens of this were not available for comparison but 
from the description and figures given by these authors it does not seem to have the 
concavity behind the anterior cardinal angle which is present in E(S.) rasilis, sp. nov. 

Remarks. The marginal denticles are not preserved in all specimens. 

Echinocythereis (Scelidocythereis) sparsa sp. nov. 
(Plate 18, figs. 4, 6, 8, 9) 

Derivation of name. Latin sparsus, scattered ; with reference to the papillae. 

Diagnosis. A species of Scelidocythereis with subrectangular carapace, dorsal 
margin slightly arched, ventral margin incurved in front of the middle. Surface 
ornamented with scattered papillae and two ventral ridges. Anterior and posterior 
marginal rims distinct. Left valve larger than right. 

Holotype. Io. 4330, a female carapace (PI. 18, figs. 8, 9). 

Paratype. Io. 4279. 

Material. 43 specimens from the locality below from three horizons (sample 
nos. 24159, 24181, and 24183). GSP BM 2539-40. 

Type locality. Zao River section. 

Type horizon. Upper Chocolate Clays, sample no. 24159. 

Description. Sexual dimorphy moderate, the males are longer in proportion 
than the females. Carapace subrectangular in side view with greatest height at the 
anterior cardinal angle. Dorsal margin slightly arched, ventral margin sinuated 
anterior to the middle. Anterior margin broadly rounded, posterior somewhat 
rounded. Right valve larger than left valve, which it over-reaches along the 
anterior and ventral margin. Anterior cardinal angle rounded. Sub central-tubercle 
indistinct, eye-tubercle rounded and distinct. Surface ornamentation consists of 
sparsely distributed papillae. There are two ventral ridges ; the top ridge bifurcates 
posteriorly but the bottom ridge is shorter. Anterior and posterior marginal 
rim fairly well-developed. Anterior margin ornamented with small and numerous 
denticles, posterior with 6-8 larger denticles. Duplicature moderately wide 
with a prominent selvage and flange-groove in the right valve particularly in the 
ventral and anteroventral regions. Radial pore canals simple, almost straight, 
irregularly spaced, 25-30 anteriorly and 12-15 posteriorly. Hinge holamphidont : 
right valve with anterior tooth — conical and projecting, followed by postjacent 
socket, shallow posteromedian groove and posterior reniform tooth. Muscle scar 



38 EARLY TERTIARY OSTRACODA 

pattern consists of four adductors in a vertical superposition and two more or less 
rounded frontal scars. 

Dimensions (mm). 

L H W 

Io. 4279 Carapace male 078 0-45 0-37 

Io. 4330 Carapace female (holotype) 076 0-49 0-39 

Comparison. Echinocythereis (Scelidocythereis) rasilia sp. nov. although smaller 
than the present species may be ancestral but has a smooth rather than a papillose 
surface. Moreover, it has a concavity behind the anterior cardinal angle and lacks 
the distinct marginal rims. 

Remarks. Echinocythereis (Scelidocythereis) sparsa has so far only been found in 
the Upper Chocolate Clays of the Zao River area. 



Genus GYROCYTHERE nov. 

Derivation of name. Greek gyros, circle ; with reference to the concentric 
arrangement of the ornamentation + cythere. 

Diagnosis. Reticulate Trachyleberididae with three or four longitudinal ridges, 
the dorsal ridge distinct from the eye-tubercle, arcuate, sloping down towards 
anterior and terminating below the eye-tubercle ; the third ridge more or less distinct 
in different species. 

Type species. Gyrocythere exaggerates sp. nov. 

Description. Sexual dimorphism rather pronounced ; the females are shorter, 
higher and wider than the males. Carapace subrectangular to subquadrate in 
lateral view. Valves almost equal. Eye-tubercle and subcentral tubercle present, 
more or less pronounced. Surface reticulate. Three to four longitudinal ridges 
present ; the dorsal ridge commences anteriorly below the eye-tubercle and is arched 
convexly upwards ; the second ridge stretches backwards from the subcentral- 
tubercle and is also arched convexly upwards, its continuation in front of the sub- 
central-tubercle being less pronounced ; the third ridge situated below the sub- 
central-tubercle slopes obliquely upwards towards the posterior and is curved con- 
vexly downward towards the anterior and the ventral ridge is confined to the 
posterior two-thirds of the carapace and culminates in a slight alar expansion in the 
posterior, almost obsolete or absent in some species. Normal pores simple, fairly 
numerous. Radial pore canals simple, irregularly spaced, more or less straight, a few 
seem to bifurcate, approximately 25 anteriorly. Inner margin and line of concresc- 
ence coincide. Duplicature moderately wide. Selvage well-marked, submarginal 
in left valve but at some distance from the outer margin in right valve. Ventral 
and anterior flange grooves well-developed in right valve. Hinge holamphidont 
with stirpate anterior tooth in right valve. Muscle scar pattern consists of four 
adductor scars in an almost vertical row and a U-shaped frontal scar, which opens to 
the anterodorsal angle. 

Comparison. This genus differs from the genus Costa in having an arcuate dorsal 



FROM WEST PAKISTAN 39 

ridge and in the less evident anterior marginal rim. Further, the subcentral- 
tubercle in Costa lies more towards the anterior. Hermanites has only two longitu- 
dinal ridges and has a concave posterodorsal slope. Gyrocythere lacks the very wide 
duplicature seen in Paracytheretta. 

Gyrocythere exaggerata sp. nov. 
(Plate 18, figs. 10-14 »' Plate 19, Plate 20, fig. 5) 

Derivation of name. Latin exaggerates, exaggerated ; with reference to the well- 
developed longitudinal ridges. 

Diagnosis. A species of the genus Gyrocythere with prominent eye-tubercle, 
bilobate subcentral-tubercle and well-developed longitudinal ridges. 

Holotype. Io. 4331, a female carapace (PI. 19, figs. 1-4). 

Paratypes. Io. 4280 + 3122-3128 

Material. 39 specimens from the Zao River section from six horizons (sample 
nos. 24145, 24147, 24148, 24150 24152). Eight specimens from the Rakhi Nala 
section from two horizons (sample nos. 3613 and 3614) . GSP BM 2541-2. 

Type locality. Zao River section. 

Type horizon. Upper Chocolate Clays, sample no. 24151. 

Description. Carapace subrectangular in the male dimorph and subquadrate in 
the female. Anterior margin broadly and evenly rounded, posterior narrow, almost 
rounded in left valve but slightly subangular in the right valve. Dorsal and ventral 
margins almost concealed in lateral outline by the dorsal and ventral ridges. Great- 
est height in the ocular region, greatest length passes through the mid-point. Anterior 
cardinal angle prominent with a concavity behind in lateral view. Valves almost 
equal. Eye-tubercle prominent, rounded and polished, stands out in lateral view. 
Subcentral-tubercle distinct and bilobate. Surface coarsely reticulate. Reticulae 
are slightly papillose in some specimens. There are four well-developed longitudinal 
ridges ; the dorsal ridge begins below the eye-tubercle anteriorly and is convex up- 
wards, whilst the median or second ridge runs from the subcentral-tubercle pos- 
teriorly and is convex upwards, its extension anterior to the subcentral-tubercle is 
less well-marked. A third ridge is intercalated between the median and the ventral 
ridges. It slopes obliquely upwards towards the posterior and is convex downwards 
in its anterior part. The ventral ridge is restricted to the posterior two-thirds of the 
carapace. It ends in a slight alar expansion in the posterior third of the carapace. 
Anterior margin denticulate, posteroventral margin with short spines present in some 
specimens. Normal pore canals simple, numerous (PI. 19, figs. 6, 7). Radial pore 
canals not very well-displayed due to the form of preservation, but appear to be 
simple, almost straight, irregularly spaced (few seem to bifurcate), with some 25 at 
the anterior margin. Line of concrescence and inner margin coincide. Duplicature 
of moderate width, 0-07 mm. anteriorly. Selvage pronounced in both valves ; it is in 
the outer third of the duplicature in right valve but submarginal in left valve. Right 
valve with well-developed7?ange groove, particularly on the venter. Muscle scars are 



4° 



EARLY TERTIARY OSTRACODA 



in a vertical row of four adductors and a U-shaped frontal scar opening towards the 
anterodorsal corner. Hinge holamphidont : 

Left valve 

Rounded socket, confluent 

with ocular sinus, seen 

in a few specimens. 

Subcorneal tooth which has Deep rounded socket 

straight anterior but convex opening into postero- 



Element 
Anterior 



Anteromedian 



Right valve 
Projecting stirpate 
tooth. 



Posteromedian 
Posterior 

Dimensions (mm). 



posterior in dorsal view. 
Denticulate bar. 
Deep, slightly elongate 
socket. 



median groove. 
Locellate groove. 
Pessular tooth, but sub- 
rectangular in lateral view. 



L 


H 


o-8i 


0-49 


o-8 3 


0-49 


078 


0-49 


076 


0-46 


071 


0-44 


071 


0-44 


077 


0-46 


072 


0-44 


079 


0-44 



w 



0-46 



Io. 3125 Left valve male 

Io. 3127 Right valve male 

Io. 4331 Carapace female (holotype) 

Io. 3126 Left valve male 

Io. 3124 Right valve female 

Io. 3128 Right valve female 

Io. 4280 Left valve male 

Io. 3120 Right valve female 

Io. 3122 Right valve male 
Comparison. This species resembles Gyrocythere perfecta sp. nov. (PI. 22, figs. 1-10) 
but differs from it in being larger and having more prominent longitudinal ridges and 
an eye-tubercle. Moreover, the subcentral tubercle in G. exaggerate/, is distinctly 
bilobate. 

Remarks. The occurrence of this species ranges through 390 ft. in the Zao River 
section and 15 ft. in the Rakhi Nala section. It seems likely that it will prove a 
useful horizon marker. 

Gyrocythere parvicarinata sp. nov. 
(Plate 20, figs. 1-4, 6-8, 12) 

Derivation of name. Latin parvus, little + carinatus, ridged; with reference to 
the longitudinal ridges. 

Diagnosis. A strongly reticulate species of the genus Gyrocythere with three 
longitudinal ridges, median ridge ill-defined, posterior subtriangular, eye-tubercle 
distinct, subcentral-tubercle well-developed. 

Holotype. Io. 4334, a male carapace (PI. 20, figs. 1, 2, 6, 7). 

Paratype. Io. 4281. 

Material. Over 100 specimens from the Rakhi Nala section from 25 horizons 
(sample nos. 3153, 3168 to 3172, 3179, 3180, 3185, 3192, 3193, 3199, 3200, 3401 to 
3405, 3407. 3409. 34 IO > 34*5 and 3417). GSP BM 2543-4. 



FROM WEST PAKISTAN 41 

Type locality. Rakhi Nala section. 

Type horizon. Green and Nodular Shales, sample no. 3407. 

Description. Sexual dimorphism distinct ; the males are more elongate than the 
females. Carapace subrectangular in side view. Anterior margin broadly rounded, 
posterior subtriangular. Dorsal margin straight but appears slightly convex in 
lateral view due to the over-reaching of the dorsal ridge, ventral margin slightly 
concave in front of the middle. Anterior cardinal angle distinct with a concavity 
behind in lateral view. Left valve slightly over-reaches right valve at anterior 
cardinal angle and posterodorsal slope. In dorsal view the greatest width lies in the 
anterior two-fifths. Subcentral-tubercle well developed. Eye-tubercle distinct. Surface 
strongly reticulate with three longitudinal ridges ; the dorsal ridge is curved con- 
vexly upwards ; the median ridge is more or less ill-defined in many specimens ; the 
third or ventral ridge is curved convexly downward anteriorly. Anterior and 
posterior marginal rims present but not high. Both anterior and posterior margins 
are denticulate. Duplicature of medium width. Selvage distinct and at some 
distance from the outer margin in right valve. Anterior and ventral flange grooves 
well-developed in right valve. Radial pore canals not clearly seen due to mineraliz- 
ation. Hinge as for the genus. 

Dimensions (mm). 

L 
Io. 4334 Carapace male (holotype) o-68 

Io. 4281 Carapace female 0-67 

Comparison. This species is smaller than Gyrocythere grandilaevis sp. nov. 
Although the longitudinal ridges are no better developed than G. grandilaevis the 
eye-tubercle and subcentral-tubercle are more prominent, the reticulation is deeper 
and wider in proportion. 

Gyrocythere grandilaevis sp. nov. 
(Plate 20, figs. 9-11, 13 ; Plate 21, figs. 1-4) 

Derivation of name. Latin grandis, large + laevis, smooth ; with reference to 
the carapace. 

Diagnosis. A species of Gyrocythere with large, reticulate, smooth carapace. 
Three longitudinal ridges, including median ridge which is not well-developed. 
Anterior and posterior marginal rims distinct. 

Holotype. Io. 4332, a female carapace (PI. 20, figs. 11, 13 ; PI. 21, figs. 3, 4). 

Paratype. Io. 4282. 

Material. 16 specimens from the locality below from four horizons (sample 
nos. 3463 to 3466). Two specimens from the Shpalai Khwara section from one 
horizon (sample no. 24692). GSP BM 2545-6. 

Type locality. Rakhi Nala section. 

Type Horizon. Shales with Alabaster, sample no. 3463. 



H 


w 


o-37 


o-34 


0-42 


o-37 



42 EARLY TERTIARY OSTRACODA 

Description. Sexual dimorphism moderate ; the males are proportionally longer 
than the females. Carapace subrectangular in lateral outline. Anterior margin 
broadly rounded, posterior margin almost rounded in left valve but with a slight 
concavity in the posterodorsal slope of the right valve. Dorsal margin almost 
straight but appears slightly convex in lateral view due to the dorsal ridge, which 
slightly over-reaches it ; ventral margin slightly concave in front of the middle. 
Valves almost equal. Subcentral-tubercle and eye-tubercle present but not pro- 
nounced. Surface reticulate ; the reticulae concentrically arranged around the 
subcentral-tubercle. There are three longitudinal ridges, a dorsal ridge curved 
convexly upward, a median or second less well-developed ridge and a ventral or 
third ridge which runs obliquely from above the anteroventral corner towards the 
posterior and is curved convexly downward in its anterior portion. Anterior and 
posterior marginal rims distinct. Anterior and posterior margins denticulate. 
Internal features not seen. 

Dimensions (mm). 

L H W 

I°- 433 2 Carapace male (holotype) 0-85 0-46 0-44 

Io. 4282 Carapace female 0-83 0-46 0-46 

Comparison. This species resembles Gyrocythere parvicarinata sp. nov. but differs 
from it in being larger. Moreover, the posterior in G. parvicarinata is subacuminate. 
G. grandilaevis is perhaps ancestral to Gyrocythere perfecta sp. nov. which is smaller 
and has stronger ornamentation. 

Gyrocythere mitigata sp. nov. 

(Plate 21, figs. 5-1 1 ) 

Derivation of name. Latin mitigatus, mellowed ; with reference to the orna- 
mentation, less emphatic than in the typical species of G. exaggerata. 

Diagnosis. A large, strongly reticulate species of the genus Gyrocythere with 
three longitudinal ridges, the median ridge almost ill-defined. 

Holotype. Io. 4333, a male carapace (P. 21, figs. 5-8). 
Paratypes. Io. 4283 + Io. 3119. 

Material. 9 specimens from the locality below from two horizons (sample nos. 
24131 and 24132). Io. 4283. GSPBM 2547-8. 

Type locality. Zao River section. 

Type horizon. Lower Chocolate Clays, sample no. 24131. 

Description. Sexually dimorphic ; the males are longer than the females. 
Carapace subrectangular in lateral view. Anterior margin broadly and evenly 
rounded, dorsal margin almost straight in reality but appears slightly convex in 
lateral view because of the over-reaching of the dorsal ridge ; posterodorsal slope 
very slightly concave particularly in the right valve, posterior extremity rounded, 
postero ventral margin curved, ventral margin almost straight. Greatest height in 
the anterior quarter, greatest length almost in the middle. Anterior and posterior 



H 


w 


o-49 


o-49 


o-49 


— 


o-47 


— 



FROM WEST PAKISTAN 43 

cardinal angles well-marked, particularly in left valve. Left valve slightly over- 
reaches the right valve in the anterodorsal corner and at the posterodorsal slope. 
Greatest width in dorsal or ventral view lies in the posterior third. Subcentral- 
tubercle prominent, eye-tubercle rounded and distinct. Surface strongly reticulate 
with three longitudinal ridges : the dorsal ridge is curved convexly upwards in the 
middle and starts anteriorly below the eye-tubercle ; the median ridge is less well- 
developed, almost ill-defined in most specimens ; it runs posteriorly from the sub- 
central-tubercle and is curved convexly upwards. The ventral ridge commences 
anteriorly above the anteroventral corner and runs obliquely upwards towards the 
posterior and culminates in the posterior third. Marginal rim is distinct at the 
anterior and posterior but less distinct along the venter. Anterior margin denti- 
culate, posterior extremity and posteroventral margin ornamented with about six 
short spines or papillae. Duplicature of moderate width. Selvage well-developed, 
subperipheral in the left valve but situated at some distance from the outer margin 
in the right valve. The right valve has a fairly deep flange groove along the venter 
and around the anterior margin. Hinge as for the genus. 

Dimensions (mm). 

L 

I°- 4333 Carapace male (holotype) o-88 

Io. 4283 Carapace female 0-83 

Io. 3119 Left valve female o-8o 

Comparison. Gyrocythere grandilaevis sp. nov. is somewhat similar to the present 

species and might even be ancestral although G. grandilaevis is smaller and has a less 

well-developed subcentral-tubercle. The dorsal and ventral ridges in G. grandilaevis 

are also less well-marked. G. mitigata differs from Gyrocythere exaggerata sp. nov. in 

being larger, having a different lateral outline and less emphatic ornamentation. 

Further, G. mitigata has three, rather than four longitudinal ridges and lacks a 

bilobate subcentral-tubercle. 

Remarks. G. mitigata has so far only been found in the Zao River section, where 
it occurs at two horizons. 

Gyrocythere perfecta sp. nov. 

(Plate 22, figs. 1-10) 

Derivation of name. Latin perfectus, perfect ; with reference to the beauty of 
the material. 

Diagnosis. Gyrocythere with strongly reticulate, concentrically arranged orna- 
mentation. Eye-tubercle, subcentral-tubercle and longitudinal ridges distinct. 

Holotype. Io. 4335, a female carapace (PI 22, figs. 3, 4, 7, 8). 
Paratypes. Io. 4284 + Io. 3120-1. 

Material. 20 specimens from the locality below from two horizons (sample 
nos. 3498 and 3499). GSP BM 2548-50. 

Type locality. Rakhi Nala section. 

Type horizon. Lower Chocolate Clays, sample no. 3499. 



44 EARLY TERTIARY OSTRACODA 

Description. Carapace subrectangular in lateral view, arrow-shaped in ventral 
view. Sexual dimorphism rather pronounced ; the females are higher and wider 
than the males. Anterior margin broadly rounded, posterior slightly subangular, 
particularly in the right valve. Dorsal margin straight but appears to be convex 
due to the over-reaching of the dorsal ridge ; ventral margin slightly concave 
anterior to the middle. Anterior cardinal angle distinct and rounded. Valves 
almost equal. Eye-tubercle distinct but not high. Subcentral-tubercle distinct, 
slightly lobate. Surface strongly and deeply reticulate, the reticulation being 
concentric around the subcentral-tubercle. Four longitudinal ridges occur : the 
dorsal ridge is convex upwards ; it commences below the eye-tubercle and culminates 
in the posterodorsal region ; the median or second ridge is also convex upwards ; it 
runs from the subcentral-tubercle towards the posterior but its continuation anterior 
to the subcentral-tubercle is not distinct ; the third ridge is convex downwards in its 
anterior half and slopes obliquely upwards towards the posterior ; the ventral ridge 
is better seen in ventral view ; it is confined in the posterior three-quarters. Anterior 
margin denticulate. There is a short posteroventral spine present in most specimens. 
Radial pore canals simple, more or less straight, irregularly spaced, few seem to 
bifurcate, about 25-28 in the anterior. Inner margin and line of concrescence 
coincide throughout. Duplicature moderately wide with a distinct selvage. In the 
right valve the selvage lies at some distance from the outer margin and the anterior 
and ventral flange grooves are distinct. Adductor scars in a vertical column of four 
and with a U-shaped frontal scar. Hinge holamphidont. 

Dimensions (mm). 

L 

Io. 4281 Carapace male 071 

I°- 4335 Carapace female (holotype) 0-71 

Io. 3121 Right valve male 0-76 

Io. 3121 Right valve female 076 

Io. 3120 Right valve female 076 

Comparison. The present species is similar in all characters to Gyrocythere 
exaggerata sp. nov. but is smaller and with a less well-marked ornamentation. On 
the other hand, the ornamentation is stronger than in Gyrocythere grandilaevis sp. nov. 
In both the morphological development and stratigraphical position, G. perfecta falls 
between G. grandilaevis and G. exaggerata. 

Remarks. G. perfecta has so far only been found in the type locality. 

Genus HERMANITES Puri 1955 
Type species. Hermania reticulata Puri 1954. 

Hermanites cracens sp. nov. 
(Plate 22, figs. 11 ; Plate 23, figs. 1-3) 

Derivation of name. Latin cracens, graceful ; with reference to the pleasing 
curve of the ridges. 



H 


w 


o-39 


0-38 


0-42 


0-42 


0-42 


0-42 


0-42 


— 


0-44 


— 



FROM WEST PAKISTAN 45 

Diagnosis. A large Hermanites with well-developed slightly curved dorsal and 
ventral ridges. Subcentral-tubercle prominent with three small curved longitudinal 
ridges behind. 

Holotype. Io. 4336, a carapace. 

Material. Only one specimen from the locality and horizon below. 

Type locality. Rakhi Nala section. 

Type horizon. Gorge Beds, sample no. 3111. 

Description. Carapace large, massive, subrectangular in lateral view. Greatest 
length through the mid-point, greatest height through the anterior cardinal angle and 
greatest width in the posterior third. Dorsal and ventral margins almost straight, 
anterior broadly and evenly rounded, posterodorsal margin very slightly concave, 
posteroventral margin and posterior extremity rounded. Anterior cardinal angle 
well-developed particularly in the left valve. Left valve slightly over-reaches the 
right at the anterior cardinal angle and posterodorsal slope. Subcentral tubercle 
prominent. Eye-tubercle rounded and distinct and with a rounded groove in front, 
particularly in the left valve. Marginal rim high in the anterior but somewhat less 
high in the posterior and venter. Surface coarsely reticulate with well-marked, 
dorsal and ventral ridges ; the dorsal ridge commences above the subcentral-tubercle 
and is slightly curved convexly upwards ; the ventral ridge slopes obliquely upward 
towards posterior and then curves sharply round towards posteroventral margin 
in posterior quarter. There are three short curved longitudinal ridges behind the 
subcentral-tubercle, the bottom one being the shortest. Anterior and posterior 
margins spinose — -anterior with numerous small spines but posterior with few 
larger spines. 

Dimensions (mm). 

L H W 

Io. 4336 Carapace 0-95 0-51 0-51 

Comparison. Hermanites palmatus sp. nov. is much smaller, has the dorsal and 
ventral ridges joined posteriorly by a transverse ridge and the ridges in front of the 
subcentral-tubercle have a palmate appearance. 

Remarks. So far only one specimen of this species has been recovered from the 
Gorge Beds of the Rakhi Nala section, where it occurs in association with Alocopocy- 
there rupina sp. nov. and Buntonia devexa sp. nov. 

Hermanites scopus sp. nov. 
(Plate 23, figs. 4-10) 

Derivation of name. Latin scopus, target ; in allusion to the fancied resem- 
blance of the ornamentation to a bull's-eye. 

Diagnosis. A species of the genus Hermanites in which ventral ridge curves down- 
ward in the middle and is joined by a short vertical ridge at its posterior end ; surface 



46 EARLY TERTIARY OSTRACODA 

coarsely reticulate with prominent subcentral-tubercle from which a ridge runs 
towards anterior margin. 

Holotype. Io. 4338, a male carapace (PI. 23, figs. 4-7). 

Paratype. Io. 4285. 

Material. 13 specimens from the Rakhi Nala section from six horizons (sample 
nos. 3499, 3610, 3613 to 3615 and 3618). Two specimens (including holotype) from 
the Zao River section from two horizons (sample nos. 24148 and 24150). GSP BM 
2552-3- 

Type locality. Zao River section. 

Type horizon. Upper Chocolate Clays, sample no. 24148. 

Description. Sexual dimorphy observed ; the males are longer in proportion 
than the females. Carapace thick-shelled, sub-rectangular in lateral view. Anterior 
margin broadly and evenly rounded, posterior slightly subtriangular. Dorsal and 
ventral margins almost straight. Valves more or less equal. Anterior cardinal 
angle well-developed. In dorsal view, greatest width lies in the posterior third. 
Eye-tubercle rounded and prominent with rounded deep groove in front (better seen 
in dorsal view). Subcentral-tubercle prominent with a ridge running towards the 
anterior margin. Surface strongly reticulate (occasionally with superimposed 
rounded spines particularly at the junction where two reticulae meet). Dorsal and 
ventral ridges well-developed : the dorsal ridge is almost straight while the ventral 
ridge is curved convexly downward in the middle culminating in a short vertical 
ridge in the posterior third. Anterior and posterior marginal rims elevated, ventral 
marginal rim somewhat less elevated. Anterior and posterior margins ornamented 
with double row of spines (not preserved in all specimens) — one row of spines lies on 
the anterior and posterior marginal rims and the second row below these rims. 
Duplicature of moderate width with subperipheral selvage. Radial pore canals and 
muscle scars not known. Hinge holamphidont : left valve hinge consists of two 
terminal sockets, median element subdivided into anteromedian subcorneal pro- 
jecting tooth and denticulate bar ; right valve hinge (seen only in a broken valve) 
consists of a stirpate, projecting anterior tooth, deep anteromedian socket, locellate 
posteromedian groove and posterior tooth (broken). 

Dimensions (mm). 

L H W 

Io. 4338 Carapace male (holotype) 0-78 0-44 0-44 

Io. 4285 Carapace female o-8i 0-46 0-49 

Comparison. This species shows some resemblance to Hermanites cracens sp. nov. 
but is smaller, has a more curved ventral ridge culminating in a short vertical ridge 
in the posterior third and lacks the three small, curved longitudinal ridges behind the 
subcentral-tubercle. 

Remarks. Hermanites scopus rarely occurs in the Lower and Upper Chocolate 
Clays of the Rakhi Nala and Zao River sections and can easily be recognized by its 
characteristic ventral ridge. 



FROM WEST PAKISTAN 47 

Hermanites palmatus sp. nov. 

(Plate 24, figs. 1-9, ii, 12) 

Derivation of name. Latin palmatus, palmate ; with reference to the palmate 
appearance of the ridges in front of the subcentral-tubercle. 

Diagnosis. Hermanites in which dorsal and ventral ridges are alate and joined 
posteriorly by a transverse ridge which is slightly concave towards posterior. Sub- 
central-tubercle prominent with palmate appearance of ridges in front. 

Holotype. Io. 4337, a female left valve (PI. 24, figs. 6, 8, 9, 11). 

Paratypes. Io. 4286 + Io. 3117-8. 

Material. 9 specimens from the Rakhi Nala section from five horizons (sample 
nos. 3613 to 3615, 3617 and 3618). 17 specimens from the Zao River section from 
four horizons (sample nos. 24131, 24150, 24152 and 24156). GSP BM 2554-5. 

Type locality. Zao River section. 

Type horizon. Upper Chocolate Clays, sample no. 24152. 

Description. Sexual dimorphism apparent ; the females being shorter than the 
males. Carapace subrectangular in lateral outline with greatest height in the region 
of the anterior cardinal angle. Dorsal and ventral margins almost straight, anterior 
margin broadly rounded, posterodorsal corner very slightly concave, posterior 
extremity and posteroventral margin rounded. Valves almost equal. Subcentral- 
tubercle prominent. Eye-tubercle rounded and distinct. Surface recticulate with 
alate dorsal and ventral ridges which are joined posteriorly by a transverse ridge 
which is slightly concave towards the posterior. Anterior and posterior marginal 
platforms compressed. Anterior and posterior marginal rims distinct. Anterior 
margin ornamented with 20-25 small spines, posterior with 6-8 larger spines. 
Duplicature of moderate width, 0-050 mm. anteriorly. Both valves have a distinct 
selvage. Hinge holamphidont : left valve hinge with fairly deep anterior socket, 
anteromedian tooth rounded, subcorneal (slightly projecting towards the anterior in 
dorsal view), posteromedian ridge denticulate and deep, slightly elongate posterior 
socket ; right valve hinge with anterior subcorneal, projecting tooth followed by deep 
postjacent socket, posteromedian shallow groove and an almost rounded, posterior 
tooth. 

Dimensions (mm). 

Io. 4286 
Io. 3117 
Io. 4337 
I0.3118 

Comparison. Hermanites scopus sp. nov. is larger, has a curved ventral ridge and 
subtriangular posterior margin. Hermanites indicus Tewari and Tandon (i960) has 
a subtriangular posterior end and lacks the transverse ridge which posteriorly joins 
the dorsal and ventral ridges. The Miocene species Hermanites purii Tewari and 
Tandon (i960) has somewhat similar lateral outline, but lacks both the transverse 





L 


H 


w 


Carapace male 


0-69 


o-37 


o-37 


Carapace female 


0-63 


o-37 


o-37 


Left valve female (holotype) 


0-73 


0-40 


— 


Left valve female 


073 


0-44 


— 



48 EARLY TERTIARY OSTRACODA 

ridge which posteriorly joins the dorsal and ventral ridges and the palmate appear- 
ance of ridges in front of the subcentral-tubercle. Moreover, the greatest width in 
Hermanites palmatus is in the posterior third, but in Hermanites purii it is a little to 
the anterior of the middle (see Tewari and Tandon, p. 158). 

Remarks. The true relationship of the present species with Hermanites indicus 
and Hermanites purii cannot be determined until topotype material from Kutch is 
available for comparison. 



Genus OCCULTOCYTHEREIS Howe 1951 
Type species. Occultocythereis delumbata Howe 195 1. 

Occultocythereis interrupta sp. nov. 
(Plate 24, figs. 10, 13-18) 

Derivation of name. Latin interruptus, broken apart ; with reference to the 
break in the dorsal ridge. 

Diagnosis. A small Occultocythereis with well-marked subangular postero- 
dorsal process which is confluent with four ridges including an oblique ridge running 
towards posteroventral region and then extending towards anteroventral corner as 
an oblique ventral ridge. 

Holotype. I04339, a female carapace (PI. 24, figs. 14, 17, 18). 

Paratype. Io. 4287. 

Material. 28 specimens from the locality below from three horizons (sample 
nos. 460-f, 460-i and 460-j). GSP BM 2556-7. 

Type locality. Sor Range section. 

Type horizon. Upper Palaeocene, sample no. 460-i. 

Description. Sexual dimorphism marked ; the females are shorter and wider 
than the males. Carapace subrectangular in side view, tapering towards the 
posterior. Dorsal and ventral margins almost straight ; the dorsal margin appears 
slightly irregular in lateral outline because of the over-reaching of the dorsal ridge ; 
anterior margin broadly and obliquely rounded, posterior narrow, slightly concave 
in posterodorsal slope but more or less rounded in posteroventral margin. Greatest 
length lies through the mid-point and greatest height at the anterior cardinal angle. 
Anterior and posterior cardinal angles well-marked particularly in the right valve. 
Valves almost equal. Eye-tubercle distinct, situated on the anterior marginal rim. 
Shell surface undulating with compressed anterior and posterior platforms. A well- 
marked, subangular posterodorsal process is confluent with four ridges : (1) a short 
ridge extends vertically towards the posterodorsal corner ; (2) a dorsal ridge runs 
towards the anterior, culminating in the anterior third of the dorsal margin — it is 
slightly convex upwards ; (3) a short ridge extends vertically below, terminating 
before reaching the mid-line, whilst the fourth ridge runs obliquely towards the pos- 
teroventral region where it is joined by an oblique ventral ridge running towards 



FROM WEST PAKISTAN 49 

the anteroventral corner. Anteromedian swelling well-developed. A marginal rim 
extends around the anterior, ventral and posterior margins, elevated on the anterior 
margin but less elevated around the venter and posterior. Small ridges run be- 
tween the anterior marginal rim and the anterior margin (these are better seen in 
ventral view). Four to five short spines ornament the posteroventral margin. 
Internal details not known. 

Dimensions (mm.) 

L H w 

Io. 4287 Carapace male 0-39 0-18 o-n 

Io. 4339 Carapace female (holotype) 0-38 0-20 0-13 

Comparison. Occultocythereis indistincta sp. nov. is much larger, has a continuous 
rather than a broken dorsal ridge and lacks the oblique posterior ridge which joins 
the posterodorsal process and the ventral ridge. 

Remarks. 0. interrupta is so far only known from the Upper Palaeocene of the 
Sor Range section. 

Occultocythereis Sp.A 
(Plate 25, figs. 1, 2, 5, 12) 

Figured specimen. Io. 3136. 

Material. Only one specimen from the locality and horizon below. 

Locality. Rakhi Nala section. 

Horizon. Lower Rakhi Gaj Shales, sample no. 3672. 

Description. Carapace subrectangular with ventral inflation. Dorsal and 
ventral margins almost straight, tapering towards the posterior ; anterior margin 
broadly and obliquely rounded, posterior narrowly rounded with a slight concavity 
in the posterodorsal corner. Greatest length runs through the middle, greatest 
height in the anterior two-fifths and greatest width in the posterior third. Anterior 
and posterior cardinal angles rounded. Valves almost equal. Eye-tubercle distinct 
but low. Subcentral-tubercle weak. Surface reticulate. Posterodorsal process 
consists of a more or less rounded tubercle which extends anteriorly in a weak dorsal 
ridge. Anterior marginal rim well-marked, ventral and posterior marginal rims less 
elevated. Posterior ornamented with 4-5 short spines. 

Dimensions (mm). 

L H w 

Io. 3136 Carapace 0-42 0-22 0-17 

Remarks. This species differs from other known species of the genus Occulto- 
cythereis in its obliquely rounded anterior margin. 

Occultocythereis spilota sp. nov. 
(Plate 25, figs. 3, 4, 6-11) 

Derivation of name. Greek spilotos, spotted ; with reference to the largish 
puncta. 



50 EARLY TERTIARY OSTRACODA 

Diagnosis. A species of Occultocythereis in which surface is ornamented with 
largish puncta. Posteroventral margin rounded, posteroventral process a short 
slightly oblique ridge well-developed in female, ill-defined in male, anteroventral 
swelling small. 

Holotype. Io. 4342, a female carapace (PI. 25, figs. 6, 7, 10, 11). 

Paratype. Io. 4288. 

Material. Four specimens from the locality below from three horizons (sample 
nos. 3173, 3174 and 3177). GSP BM 2558-9. 

Type locality. Rakhi Nala section. 

Type horizon. Green and Nodular Shales, sample no. 3177. 

Description. Dimorphic ; the females are higher and wider than the males. 
Carapace subrectangular in lateral view with greatest length in the middle and 
greatest height in the anterior third. Anterior margin broadly rounded, postero- 
dorsal slope very slightly concave, posteroventral margin rounded, dorsal and ventral 
margins almost straight, very slightly converging towards the posterior. Anterior 
cardinal angle rounded, posterior cardinal angle distinct about no . Valves almost 
equal. In dorsal view the greatest width lies in the posterior third. Eye-tubercle 
more or less distinct. Subcentral-tubercle present but not pronounced with a small 
swelling below and slightly anterior to it. Surface ornamented by large puncta. The 
posterodorsal process is a short projecting ridge extending vertically towards the 
mid-line but not reaching it. It extends anteriorly in a short dorsal ridge termina- 
ting in the anterior third of the dorsal margin. The posteroventral process is a short 
slightly oblique ridge lying in the posteroventral swelling. In the male dimorph 
the posteroventral swelling is less well-developed and the posteroventral ridge ill- 
defined. Anterior marginal rim prominent, ventral and posterior marginal rims less 
prominent. Anterior marginal area ornamented by numerous, short ridges lying 
between the rim and the margin. Posteroventral margin decorated by four to five 
short spines. 

Dimensions (mm). 

L H w 

Io. 4288 Carapace male 0-38 0-21 0-13 

Io. 4342 Carapace female (holotype) 0-38 0-22 0-16 

Comparison. Occultocythereis peristicta sp. nov. Morphotype C is larger, has a 
vertical rather than an oblique posteroventral ridge joining the second posterior 
tubercle and the ventral ridge. Further, it lacks the dorsal ridge and the short 
ridges between the anterior rim and the anterior margin. 

Occultocythereis peristicta sp. nov. 
(Plate 25, figs. 13-17 ; Plate 26 ; Plate 27, figs. 1-2) 

Derivation of name. Greek peristiktos, punctate or dappled. 

Diagnosis. A punctate group of morphotypes of the genus Occultocythereis with- 



FROM WEST PAKISTAN 51 

out a dorsal ridge, ventral ridge well-marked, anteromedian swelling distinct, 
posterodorsal tubercle present. 

Holotype. Io. 4341, a female carapace (PL 25, figs. 15) ; (PI. 26, figs. 2, 3). 

Paratypes. Io. 4289-93 + Io. 3137-40. 

Material. Approximately 800 specimens from the Rakhi Nala section from 42 
horizons (sample nos, 3160, 3163, 3167, 3170, 3171, 3173, 3174, 3177, 3179, 3180, 
3186-3194, 3197 to 3200, 3401 to 3405, 3407, 3409, 3410, 3415, 3418 to 3423, 3428, 
3432, 3434 and 3435). GSP BM 2560-65. 

Type locality. Rakhi Nala section. 

Type horizon. Upper Rakhi Gaj Shales, sample no. 3167. 

Description. Sexual dimorphism rather pronounced, the males are longer in 
proportion than the females. Carapace subrectangular or wedge-shaped in lateral 
outline. Dorsal and ventral margins almost straight, tapering towards the posterior, 
anterior margin broadly and evenly rounded, posterior narrow, slightly subangular 
in the middle or almost rounded. Greatest length passes through the middle, 
greatest height lies at the anterior cardinal angle which is fairly well-developed. Left 
valve slightly over-reaches the right valve at the anterior cardinal angle and in the 
region of the posterodorsal slope. Eye-tubercle rounded and distinct, lying on the 
anterior marginal rim. Subcentral or anteromedian swelling distinct, either elongate 
or almost rounded (elongate in most morphotypes) . There is no dorsal ridge. Ventral 
ridge fairly well-developed, short in most morphotypes, either almost straight or runs 
slightly obliquely towards the posterior end where it may be connected to the second 
posterior tubercle or to the posterodorsal tubercle by means of a short vertical ridge. 
A dorsal ridge runs between the second posterior tubercle and the anteromedian 
swelling in some morphotypes. Anterior marginal rim high, ventral marginal rim 
less distinct, posterior marginal rim distinct. Short spines decorate the anterior and 
posterior margins. 

Trends of variants : — 

1. Become sparsely punctate. 

2. Gain second posterior tubercle, which may join either the posterodorsal 
tubercle or the ventral ridge. 

3. Become wedge-shaped. 

Remarks. 0. peristicta commonly occurs in the Upper Rakhi Gaj Shales, Green 
and Nodular Shales and Rubbly Limestones of the Rakhi Nala section. 
This species may be divided into the following morphotypes : 

Morphotype A 

(PL 25, figs. 13-17 ; PL 25, figs. 1-3). 

This has a well-delimited vertical posterodorsal tubercle. There is no second 
posterior tubercle. The anteromedian swelling is less well-developed. The ventral 



52 EARLY TERTIARY OSTRACODA 

ridge is almost straight, short, confined in the mid-ventral region. The surface is 
densely punctate. 

Dimensions (mm). 

L H w 

Io. 4292 Carapace male 0-43 0-22 o-n 

Io. 4341 Carapace female (holotype) 0-42 0-23 0-16 

Morphotype B 
(PI. 26, figs. 4-9) 

This is close to Morphotype A but has a more sparsely punctate surface and a 
second posterior tubercle. In addition, the present morphotype has a well-developed, 
somewhat elongate anteromedian swelling. 

Dimensions (mm). 

L H W 

Io. 4293 Carapace male 0-44 0-22 0-15 

Io. 4291 Carapace female 0-40 0-22 0-16 

Morphotype C 
(PL 26, figs. 10-15) 

This has a higher carapace than the other morphotypes. The ventral ridge runs 
slightly obliquely towards the posterior. It is joined posteriorly to the second 
posterior tubercle by a short vertical ridge. The anteromedian swelling and the 
second posterior tubercle form a broken diagonal ridge. 

Dimensions (mm). 

Io. 4289 Carapace male 
Io. 4290 Carapace female 





L 


H 


w 




o-45 


0-26 


0-17 




0-44 


0-25 


0-18 


Morphotype D 








(PL 27, figs. 1-6) 









The carapace is much more elongate than Morphotype A, B, C and E. The dorsal 
and ventral margins taper very slightly towards the posterior. An oblique posterior 
ridge joins the posterodorsal tubercle, the second posterior tubercle and the posterior 
end of the ventral ridge. The ventral ridge commences above the anteroventral 
corner, slopes obliquely upwards towards the posterior and meets the oblique 
posterior ridge in the posterior quarter. A diagonal ridge which may or may not be 
continuous passes through the second posterior tubercle and the anteromedian 
swelling. 

Dimensions (mm). 

L 
Io. 3146 Carapace male 0-51 

Io. 3139 Carapace female 0-51 



H 


W 


0-24 


0-16 


0-24 


0-17 



L 


H 


W 


o-39 


0-20 


0-13 


o-37 


0-20 


0-13 



FROM WEST PAKISTAN 53 

MORPHOTYPE E 

(PI. 27, figs. 7-12) 
This is very similar to Morphotype B, but has a wedge-shaped carapace. 
Dimensions (mm). 

Io. 3137 Carapace male 
Io. 3138 Carapace female 

Occultocythereis indistincta sp. nov. 
(Plate 27, figs. 13-15 ; Plate 28, figs. 1-4) 

Derivation of name. Latin indistinctus, dim or obscure ; named from the 
absence of well-marked diagnostic characters. 

Diagnosis. A species of the genus Occultocythereis with a well-developed dorsal 
ridge ending posteriorly in a large subangular posterodorsal process, ventral ridge 
oblique running from anteroventral corner towards posterior, surface ornamentation 
consists of indistinct puncta. 

Holotype. Io. 4340, a female carapace (PL 27, figs. 15 ; PL 28, figs. I, 3, 4). 

Paratypes. Io. 4294 + Io. 3135. 

Material. 44 specimens from the locality below from seven horizons (sample 
nos. 3499, 3614, 3615, 3621, 3625, 3648 and 3649). GSP BM 2566-7. 

Type locality. Rakhi Nala section. 

Type horizon. Lower Chocolate Clays, sample no. 3499. 

Description. Sexual dimorphism apparent ; the males are more elongate, less 
high and less wide than the females. Carapace subrectangular, slightly tapering 
towards the posterior. Dorsal margin straight but irregular in side view due to the 
over-reaching of the dorsal ridge, ventral margin almost straight, anterior margin 
broadly and evenly rounded, posterior narrow, subangular in the middle with 
slightly concave posterodorsal slope. Greatest length lies in the middle, greatest 
height in the anterior third. Anterior cardinal angle well-developed particularly in 
left valve, posterior cardinal angle rounded in the right valve but pointed in left 
valve. Left valve over-reaches right valve in the region of anterior cardinal angle 
and posterodorsal slope. Eye-tubercle distinct. Surface ornamented with small, 
indistinct puncta. Anteromedian swelling (which perhaps represents a subcentral- 
tubercle) distinct. A well-marked dorsal ridge commences behind the eye-tubercle 
and is slightly convex upward in the middle terminating in a large subangular 
posterodorsal process. In most specimens it is ornamented with three small tubercles 
which lie at some distance from one another. Ventral ridge runs obliquely from the 
anteroventral corner towards the posterior, culminating in the posterior third. (In 
some specimens it is not well-developed) . A small tubercle is present in the postero- 



L 


H 


W 


o-47 


0-24 


— 


o-43 


0-22 


0-13 


o-43 


0-24 


o-i6 



54 EARLY TERTIARY OSTRACODA 

median part of the carapace (halfway between the dorsal and ventral ridges) in a few 
specimens. A high marginal rim runs round the anterior extending along the venter 
and posterior as a less high rim. Anterior and posterior margins ornamented with 
short spines. Duplicative wide in anterior and posteroventral regions. Selvage 
distinct and lies at some distance from the outer margin. Radial pore-canals and 
muscle scars not determinable. Hinge as for the genus. 

Comparison. Occultocythereis mutabilis abducta Triebel (1961) is very similar, but is 
larger, has a different posterior end, less well-developed subcentral-swelling and 
posterodorsal tubercle. Occultocythereis mutabilis mutabilis Tiebel (1961) has a 
vertical posteroventral ridge in the right valve of the male and in both valves of the 
females. 

Dimensions (mm). 

Io. 4294 Right valve male 

I°- 3 X 35 Carapace male 

Io. 4340 Carapace female (holotype) 

Remarks. 0. indistincta has so far been found in the Lower and Upper Chocolate 
Clays of the Rakhi Nala section. 



Genus PAT AGON ACY THERE Hartmann 1962 

Type species. Patagonacy there tricostata Hartmann 1962. 

Remarks. The species here assigned with query to Patagonacy there differs in 
details of muscle scar pattern both from the type species described by Hartmann and 
from the two species described by Benson (1964) from the Antarctic. In common 
with the described species it shows the three longitudinal ridges in which a characteris- 
tic posterodorsal loop joins the upper two. 

Patagonacy there ? nidulus sp. nov. 
(Plate 28, figs. 5-12 ; Plate 29, figs. 1-4) 

Derivation of name. Latin nidulus, small bird's nest ; with reference to the 
reticulate complex of the subcentral node. 

Diagnosis. Carapace highly reticulate in which ventral ridge culminates ab- 
ruptly in posterior third, subcentral-tubercle prominent. 

Holotype. Io. 4349, a female carapace (PI. 28, figs. 9-12). 

Paratypes. Io. 4295 + Io. 3096-8. 

Material. Over 400 specimens from the Zao River section from 16 horizons 
(sample nos. 24155 to 24157, 24159, 24166, 24170, 24173, 24175 to 24178, 24180, 
24183, 24185, 24187 and 24193). Approximately 60 specimens from the Rakhi 
Nala section from 13 horizons (sample nos. 3624, 3625, 3628, 3631, 3634, 3640 to 3642, 
3645, 3646, 3649, 3658 and 3662). GSP BM 2568-9. 



FROM WEST PAKISTAN 



55 



Type locality. Zao River section. 

Type horizon. Upper Chocolate Clays, sample no. 24173. 

Description. Carapace subrectangular in side view with dorsal and ventral 
margins almost straight, subparallel ; anterior broadly rounded, posterodorsal margin 
very slightly concave (particularly in the right valve), posterior extremity and 
posteroventral margin rounded. Anterior cardinal angle well-developed in both 
valves ; posterior cardinal angle in the left valve obtuse and well-marked but in the 
right valve it is not very well developed. Left valve over-reaches the right valve 
slightly at the anterior cardinal angle and at the posterodorsal slope, otherwise 
the two valves are equal in size. In the dorsal view the greatest width passes 
either through the subcentral-tubercle or through the posterior third with a 
sulcus in between. Eye-tubercle rounded, polished and distinct ; subcentral-tubercle 
prominent, composed of reticulate complex. Shell surface strongly reticulate with 
three longitudinal ridges : the ventral ridge slopes obliquely upward towards the 
posterior, ending abruptly just before reaching the compressed posterior platform; 
the median ridge springs from the subcentral node, stretching backward to join the 
ventral ridge and forms a posterodorsal loop. (In some specimens at certain 
horizons longitudinal ridges are not well-developed.) A marginal rim runs round the 
anterior, ventral and posterior margins — it is upraised around the anterior margin. 
Anterior margin ornamented with approximately 20 small spines, posterior margin 
with 6-8 spines. Normal fore canals fairly numerous (these become exaggerated in 
specimens cleaned in ultrasonic vibrator). Radial pore canals simple, nearly 
straight, irregularly spaced ; few cross one another. There are approximately 40 
anterior radial pore canals and about 20 posterior canals. Inner margin and line of 
concrescence coincide. Duplicature of moderate width (0-073 mm. at anterior, 
0-06 mm. at posterior extremity). Selvage prominent, submarginal in left valve, 
at some distance from the margin in the right valve. Flange groove well-developed 
(particularly in the right valve) on the venter and around the anterior margin. 
Adductor muscle scars are in a vertical column of four elongate scars, the second from 
the top being longest and the bottom one the shortest. There are two frontal scars, 
the top one is smaller and almost rounded, but the bottom one is ovate. Hinge 
holamphidont : 



Element 


Left valve 


Right valve 


Anterior 


Deep socket bounded on 


Strongly projecting 




venter, confluent with 


slightly stirpate tooth 




ocular sinus. 


with a concavity on 
anterior in dorsal view. 
Ocular sinus opens below 
and slightly anterior to it. 



Anteromedian 



Conical tooth with 
straight anterior and 
convex posterior in 
dorsal outline. 



Deep rounded socket. 



56 



EARLY TERTIARY OSTRACODA 



Element 

Posteromedian 

Posterior 



Left valve 
Denticulate bar. 
Deep socket bounded 
on venter. 



Right valve 
Locellate groove. 
Tooth which in dorsal view 
appears pessular but in 
reality is semicircular or 
slightly trilobate. In 
oblique view it can be 
seen that the line of 
concrescence deviates in 
the neighbourhood of the 
posterior tooth so that 
only the outside of the 
semi-circular tooth is 
bilamellar thus enclosing 
a monolamellar core formed 
by the invagination of the 
line of concrescence. 



Dimensions (mm). 





L 


H 


w 


Carapace male 


o-8o 


0-44 


0-41 


Carapace female (holotype) 


074 


0-44 


o-39 


Left valve female 


075 


o-45 


— 


Right valve female 


076 


0-44 


— 


Right valve male 


o-8o 


o-45 


— 



10. 3096 
Io. 4349 

10. 3097 
Io. 3098 
Io. 4295 

Comparison. The presence of a reduced ventral ridge, which does not reach the 
posterior marginal rim, separates this species from Patagonacy there tricostata Hart- 
mann, Patagonacy there devexa (Muller) and Patagonacy there longiducta antarctica 
Benson. Patagonacy there tricostata Hartmann (1962) has a smaller and more 
elongate carapace and three rather than two frontal scars. Patagonacy there devexa 
(Muller) Benson (1964) is larger, has narrow anterior and posterior vestibules, split 
adductor scars and ill-defined median and dorsal ridges including the posterodorsal 
loop. (Comparative material of this species from the British Antarctic region was 
obtained through the courtesy of Dr. R. C. Whately of Aberystwyth.) Patagona- 
cythere longiducta antarctica Benson (1964) is about the same size, has a more concave 
posterodorsal slope and the two median adductor scars are split. 

Remarks. The present species commonly occurs in the Zao River and Rakhi 
Nala sections, where it has a short vertical range. It is thus a very useful species for 
correlation in this region. Patagonacy there has so far only been described from cold 
water regions, but P ? induhis occurs here in a warm water environment. A new 
generic assignment will therefore probably be necessary at a later time. 



Genus PHALCOCYTHERE nov. 

Derivation of name. Greek phalkes, beam or rib of a ship ; with reference to 
the ventral ridge + cythere. 



FROM WEST PAKISTAN 57 

Diagnosis. Reticulate Trachyleberididae with a ventral ridge ; with or without 
spines or papillae ; mostly with pronounced posterodorsal process. 

Type species. Cythere horrescens Bosquet 1852. 

Description. Sexual dimorphism present in most of the species. Carapace 
subrectangular to subquadrate in lateral outline. Anterior margin broadly rounded, 
posterodorsal margin very slightly concave, posterodorsal margin either curved or 
almost straight, dorsal margin almost straight or slightly convex (but appears 
irregular in lateral outline in many species due to surface ornamentation), ventral 
margin slightly concave in front of the middle or nearly straight (over-reached by a 
ventral ridge in lateral view in some species). Valves almost equal in size although 
the right valve over-reaches the left at the anterior margin. Subcentral-tubercle 
more or less well-developed. Eye-tubercle distinct. Surface reticulate with or 
without superimposed papillae or spines. A posterodorsal process is generally 
present. A ventral ridge more or less prominent is always present ; it is either 
straight or slightly curved convexly downward in the middle culminating in the 
posterior fourth usually in a spine or an ala. Anterior and posterior marginal rims 
always present, more or less distinct. Radial pore canals simple, almost straight, 
irregularly spaced, sometimes crossing one another, fairly numerous (approximately 
30 anteriorly in the type species). Line of concrescence and inner margin coincide. 
Duplicature fairly wide. Selvage more or less pronounced, submarginal in left valve 
but at some distance in the right valve. Right valve with a deep and well-developed 
anterior and ventral flange groove. Adductor scars in a vertical column of four 
elongate scars with two almost rounded frontal scars (see description of P. horrescens). 
Hinge holamphidont. 

Comparison. Hirsutocy there Howe 195 1 has a wider duplicature and lacks a 
ventral ridge. Australicy there Benson 1964 is a much larger genus in which fine 
pittings occur within the reticulae. The two median adductor scars are also divided 
into two. Moreover, Australicythere has a posterior vertical ridge and a less promin- 
ent ventral ridge not ending in a spine posteriorly. Bradleya Hornibrook 1952 has 
both dorsal and ventral ridges, in this respect it differs from Phalcocythere which has 
only a ventral ridge. 

Remarks. This genus is so far known from the Eocene of the Paris Basin, West 
Pakistan, Tanzania and an undescribed species from the Aquitaine Basin. 

Phalcocythere horrescens (Bosquet) 
(Plate 29, fig. 5 ; Plate 30, figs. 1-6 ; Plate 33, figs. 12, 13) 

1852 Cythere horrescens Bosquet, p. 119, pi. 6, fig. 5. 

1852 Cythere thierensiana Bosquet (pars), p. 98. 

1852 Cythere nebulosa Bosquet, p. 105, pi. 5. fig. 8. 

1955 Trachyleberis horrescens (Bosquet), Apostolescu, p. 272, pi. 8, figs. 125-126. 

1957 Hirsutocy there horrescens (Bosquet), Keij, p. 101, pi. 15, fig. 4 ; pi. 17, figs.6-7. 

Diagnosis. Phalcocythere in which posteroventral margin is straight in left valve 
but curved in the right with five or six large spines, shell surface ornamented by well- 



L 


H 


o-6o 


o-33 


o-59 


o-33 


072 


o-37 


o-59 


o-33 


0-63 


o-37 



58 EARLY TERTIARY OSTRACODA 

developed spines superimposed on reticulations ; ventral ridge and posterodorsal 
process well-marked. 

Figured specimens. Io. 4253-7. 

Material. 8 specimens from Grignon, Paris Basin, from the Lutetian IV (sample 
no. CAB 1002, Keij 1957, p. 19). 5 specimens from Villiers-St. -Frederic, Paris 
Basin, from the same horizon. 

Type locality. Grignon, Paris Basin. 

Type horizon. Lutetian. 

Dimensions (mm). 

Io. 4253 Left valve 

Io. 4257 Left valve 

Io. 4254 Left valve 

Io. 4255 Right valve 

Io. 4256 Right valve 

Comparison. This species shows some affinity to Phalcocythere retispinata sp. nov. 
but has a more spinose surface, less tapering carapace and a better developed 
subcentral-tubercle. Further, P. horrescens has straight postero ventral margin in 
the right valve, different posterodorsal process and less prominent eye-tubercle which 
lies below and slightly posterior to the anterior cardinal angle. 

Remarks. The present species has been redescribed by Keij (1957) in detail, 
where, although he ascribed it to the genus Hirsutocy there, he noted that it lacked the 
very wide duplicature of that genus. 

Adult specimens vary in size. According to Apostolescu (1955, p. 272), they 
range from 0-52 mm. to 0-70 mm. in length. 

Phalcocythere improcera sp. nov. 
(Plate 30, figs. 7-12 ; Plate 31, figs. 1-4) 

Derivation of name. Latin, improcerus, short ; with reference to the carapace. 

Diagnosis. A small Phalcocythere in which the prominent ventral ridge possesses 
an alar expansion ; posteroventral margin slightly protracted towards the venter, 
subcentral-tubercle prominent. 

Holotype. Io. 4344, a male carapace (PI. 31, figs. 1, 2 ; PI. 30, figs. 8, 9). 

Paratypes. Io. 4296 + Io. 4258-9. 

Material. 68 specimens from the Sor Range Section from four horizons (sample 
nos. 460-i, 460-j, 460-I and 460-n). GSP BM 2570-1. 

Type locality. Sor Range section. 

Type horizon. Upper Palaeocene, sample no. 460-i. 

Description. Carapace subrectangular in the male dimorph and sub-quadrate 
in the female. Sexual dimorphy is rather marked ; the males are longer in proportion 



FROM WEST PAKISTAN 59 

than the females. Anterior margin broadly rounded, posterodorsal margin very 
slightly concave, posteroventral margin rounded and slightly protracted towards the 
venter. Dorsal margin straight but appears irregular in lateral view because of the 
surface ornamentation ; ventral margin nearly straight (concealed in side view by 
the ventral ridge) . Anterior and posterior cardinal angles well-developed in the right 
valve but more or less rounded in the left valve. Right valve slightly over-reaches 
the left at the anterior margin but the left valve over-reaches the right in the region 
of the posterodorsal slope. Subcentral-tubercle prominent. Eye-tubercle distinct, 
rounded and glassy. Shell surface deeply reticulate with superimposed papillae or 
spines, the ornamentation extending onto the prominent ventral ridge (over-reaching 
the ventral margin in lateral view) which also develops an alar expansion. The 
posterodorsal process is developed as a short curved horn-like ridge in specimens with 
papillose ornamentation but is a projecting, blade-like process in specimens having a 
spinose surface. Anterior and posterior marginal rims distinct. Anterior margin 
finely denticulate with 20-22 denticles, posteroventral margin with 7-8 short spines. 
Normal pore canals fairly numerous, one to each reticule. (These become exagger- 
ated in specimens cleaned in the ultrasonic vibrator). Radial pore canals not very 
well preserved but appear to be simple, more or less straight, irregularly spaced, 
some crossing one another, approximately 35 anteriorly. Line of concrescence and 
inner margin coincide. Dupiicature moderately wide. Selvage prominent — sub- 
marginal in the left valve but situated in the outer two-fifths of the dupiicature in 
right valve which also has a deep and well marked anterior and ventral flange groove. 
Hinge not clearly seen but appears to be holamphidont. 

Dimensions (mm). 

L 
Io. 4344 Carapace male (holotype) 0-49 

Io. 4258 Carapace female 0-49 

Io. 4295 Left valve female 0-46 

Io. 4296 Right valve female 0-46 

Comparison. Distinguished from the other known species of the genus Phalco- 
cythere by its small size and the posteroventral margin slightly drawn out towards 
the venter particularly in the right valve. 

Remarks. The surface ornamentation is variable. Most of the specimens 
examined have a combination of reticulations and papillae but in a few specimens 
spines are superimposed on reticulations. 

Phalcocythere rete sp. nov. 
(Plate 31, figs. 5-12) 

Derivation of name. Latin rete, net ; with reference to the surface ornament- 
ation. 

Diagnosis. Reticulate Phalcocythere in which eye-tubercle is prominent, ventral 
ridge present but not prominent, dorsal margin slightly convex particularly in 
female. 



H 


w 


0-29 


0-27 


0-30 


0-29 


0-28 


— 


0-27 


— 



60 EARLY TERTIARY OSTRACODA 

Holotype. Io. 4348, a female right valve (PI. 31, figs. 11). 

Paratypes. Io. 4297 + Io. 3099 + Io. 3141. 

Material. 14 specimens including the holotype from the Sor Range section from 
one horizon (sample no. 460-i). GSP BM 2572-3. 

Type locality. Sor Range section. 

Type horizon. Upper Palaeocene, sample no. 460-i. 

Description. Sexual dimorphy rather strong ; the males are longer, less high and 
less wide than the females. Carapace subrectangular to subquadrate in lateral view 
with a slight taper towards the posterior. Dorsal margin slightly convex particularly 
in the female, ventral margin almost straight, anterior broadly and evenly rounded, 
posterodorsal slope very slightly concave, posteroventral margin rounded. Left 
valve slightly over-reaches the right at the anterior margin. Subcentral-tubercle 
distinct, eye-tubercle prominent, rounded and polished. Shell surface reticulate, the 
reticulae are slightly papillose. The ventral ridge is present but not prominent, 
sloping obliquely upward towards the posterior and culminating in the posterior 
third. Marginal rim distinct. Anterior and posterior margins denticulate. Radial 
pore canals simple, straight, slightly thicker on the proximal end, irregularly spaced, 
about 30 anteriorly. Inner margin and line of concresence coincide. Dupiicature 
fairly wide, 0-060 mm. anteroventrally. Selvage well-developed — submarginal in 
left valve but almost in the middle in the right valve. There is a deep anterior and 
ventral flange groove in the right valve. Hinge not clearly distinguished due to 
mineralization but presumably holamphidont. 

Dimensions (mm). 

L 
Io. 3099 Carapace male 0-65 

Io. 4297 Carapace female 0-47 

Io. 3141 Left valve female 0-46 

Io. 4348 Right valve female (holotype) 0-46 

Comparison. Phalcocythere retispinata sp. nov. is a closely related species but has 
a reticulate and spinose surface, a more elevated ventral ridge and a well-developed 
posterodorsal process. 

Phalcocythere retispinata sp. nov. 
(Plate 31, figs. 13-17 ; Plate 32, figs. 1-3) 

Derivation of name. Latin rete, net + spinatus, spined ; with reference to the 
surface ornamentation. 

Diagnosis. Phalcocythere with a prominent ventral ridge with alar expansion, 
surface ornamentation a combination of reticulations and spines, subcentral-tubercle 
present but not pronounced, eye-tubercle prominent, posterodorsal process well- 
marked. 

Holotype. Io. 4345, a female carapace (PL 31, figs. 15, 16 ; PL 32, figs. 2, 3). 

Paratype. Io. 3165. 



H 


w 


o-35 


0-24 


o-35 


0-27 


o-35 


— 


o-35 


— 






FROM WEST PAKISTAN 61 

Material. Six specimens from the below locality from three horizons (sample 
nos. 460-i, 460-j and 460-0). GSP BM 2574. 

Type locality. Sor Range section. 

Type horizon. Upper Palaeocene, sample no. 460-i. 

Description. Sexual dimorphism rather pronounced ; the females are higher and 
wider than the males. Carapace tapering towards the posterior, subrectangular in 
side view. Dorsal margin nearly straight in the male dimorph but very slightly 
convex in the female (appears to be irregular in dorsal view due to ornamentation) ; 
ventral margin almost straight but concealed by the ventral ridge in side view ; 
anterior broadly rounded, posterodorsal margin very slightly concave ; postero- 
ventral margin rounded. Greatest length lies below mid-point, greatest height in 
the anterior third. Anterior and posterior cardinal angles well-developed. Right 
valve very slightly over-reaches the left at the anterior margin. Subcentral-tubercle 
present but not pronounced. Eye-tubercle prominent, rounded and polished. Orna- 
mentation consists of reticulations and spines. The spines are of variable size. A 
posterodorsal process consists usually of a large spine, which stands out in lateral 
view. The ventral ridge is high and with an alar expansion, slightly concave in the 
middle culminating in the posterior third with a pointed end. Anterior and posterior 
marginal rims more or less distinct and decorated with a row of spines. Anterior 
and posterior margins denticulate. Internal characters not seen. 

Dimensions (mm). 

L 
Io. 3165 Carapace male 0-64 

Io. 4345 Carapace female (holotype) 0-64 

Comparison. Phalcocythere improcera sp. nov. is much smaller, has deeper 
reticulations and a posteroventral margin slightly drawn out towards the venter. 

Phalcocythere sentosa sp. nov. 

(Plate 32, figs. 4-10) 

Derivation of name. Latin sentosus, rough ; with reference to the surface 
ornamentation. 

Diagnosis. A species of the genus Phalcocythere in which ventral ridge is present 
but not high ; surface ornamentation consists of combination of reticulations and 
papillae ; posterodorsal process a small tubercle or short spine. Subcentral-tubercle 
distinct, eye-tubercle prominent. 

Holotype. Io. 4346, a male carapace (PI. 32, figs. 4, 5, 8, 10). 

Paratype. Io. 4298. 

Material. 67 specimens from the Rakhi Nala section from 11 horizons (sample 
nos. 3153, 3165, 3167, 3169, 3170, 3173 to 3177 and 3180) . GSP BM 2575-6. 

Type locality. Rakhi Nala section. 

Type horizon. Upper Rakhi Gaj Shales, sample no. 3167. 



H 


w 


o-37 


0-27 


o-39 


0-32 



62 EARLY TERTIARY OSTRACODA 

Description. Strongly dimorphic, the females are less elongate than the males. 
Carapace subrectangular in lateral view. Anterior broadly rounded, posterodorsal 
slope very slightly concave, posteroventral margin rounded, dorsal margin almost 
straight, appearing irregular in lateral view, ventral margin slightly concave anterior 
to the middle. Right valve slightly over-reaches left valve at the anterior margin 
but is over-reached by the latter in the region of the posterodorsal slope. Anterior 
and posterior cardinal angles well-developed, particularly in the right valve. Eye- 
tubercle rounded and prominent, projecting out from the eye-socket. Subcentral- 
tubercle distinct. Surface reticulate with superimposed papillae, posterodorsal 
process either a small more or less rounded tubercle or a cluster of short spines ; ventral 
ridge present but not elevated. Anterior and posterior marginal rims distinct. 
Anterior margin denticulate, posteroventral margin papillose. Internal details not 
observed. 

Dimensions (mm). 

L H w 

Io. 4346 Carapace male (holotype) 0-56 0-32 0-25 

Io. 4298 Carapace female 0-55 0-32 0-29 

Comparison. Phalcocythere rete sp. nov. is larger than the present species, has a 
less papillose surface and slightly convex dorsal margin in the female. 

Remarks. So far only known from the Rakhi Nala section. The posterodorsal 
process varies; in some specimens it is almost a rounded tubercle but in others it is a 
short spine. 

Phalcocythere dissenta sp. nov. 
(Plate 32, figs. 11-18) 

Derivation of name. Latin dis, not -f- sentus, spiny. 

Diagnosis. A reticulate species of the genus Phalcocythere with dorsal and ventral 
margins sub-parallel, anterior rim ornamented like a scallop or flute, subcentral- 
tubercle prominent, eye-tubercle and ventral ridge distinct. 

Holotype. Io. 4343, a male carapace (PL 32, figs. 11, 14, 18). 

Paratype. Io. 4299. 

Material. Approximately 400 specimens from the locality above from six 
horizons (sample nos. 3454, 3456, 3460 to 3462 and 3464) and 6 specimens from the 
Zao River section from one horizon (sample no. 24107). GSP BM 2577-8. 

Type locality. Rakhi Nala section. 

Type horizon. Shales with Alabaster, sample no. 3456. 

Description. Sexual dimorphism marked, the presumed males are more 
elongate, less high and less wide than the females. Carapace sub-rectangular in lateral 
outline with sub-parallel dorsal and ventral margins. Anterior margin broadly 
rounded ; posterodorsal slope more or less straight ; posteroventral margin rounded ; 
dorsal margin slightly convex particularly in the female ; ventral margin almost 
straight, although partly hidden by the ventral ridge in lateral view. Greatest 



H 


w 


o-44 


0-32 


o-44 


o-44 



FROM WEST PAKISTAN 63 

length passes through mid-point, greatest height in the anterior third and greatest 
width in the anterior two-fifths. Anterior and posterior cardinal angles protruding. 
Valves almost equal. Subcentral-tubercle prominent, eye-tubercle distinct and 
situated below the cardinal angle. Anterior marginal rim distinct, and ornamented 
with seven very short ridges with small depressions in between (like flutes or scallops), 
posterior rim more or less distinct. Surface reticulate with a distinct ventral ridge 
which slopes obliquely upwards posteriorly ending in the posterior third. In many 
specimens the posterior ending is pointed or spinose. Internal details not determin- 
able, all specimens being complete carapaces. 

Dimensions (mm). 

L 
Io. 4343 Carapace male (holotype) o-6o 

Io. 4299 Carapace female 0-56 

Comparison. This species shows some resemblance to Phalcocythere rete sp. nov. 
but is smaller and has subparallel rather than tapering dorsal and ventral margins. 
It differs from Phalcocythere improcera sp. nov. and Phalcocythere sentosa sp. nov. in 
shape and surface ornamentation. 

Remarks. P. dissenta seems to be restricted to the Shales with Alabaster only 
and has been found in the Rakhi Nala and Zao River sections. It is abundant in the 
Rakhi Nala section but rare in the Zao River area. 



Phalcocythere spinosa sp. nov. 
(Plate 33, figs. 1, 2, 7, 8) 

Derivation of name. Latin spinosus, spiny. 

Diagnosis. A species belonging to the genus Phalcocythere with short spines 
and/or papillae superimposed on reticulations ; ventral ridge distinct and terminating 
in a spine in posterior third ; posterodorsal process well-marked and blade-like. 

Holotype. Io. 4347, a carapace. 

Material. 16 specimens from the Zao River section from one horizon (sample 
no. 24161). GSP BM 2579. 

Type locality. Zao River section. 

Type horizon. Upper Chocolate Clays, sample no. 24161. 

Description. Carapace subrectangular in side view. Dorsal margin almost 
straight, appearing to be irregular in lateral view due to ornamentation ; ventral 
margin more or less straight but hidden by the ventral ridge in side view ; anterior 
margin broadly rounded ; posterodorsal margin slightly concave ; posteroventral 
margin rounded. Greatest length passes through the mid-point and greatest height 
passes through the anterior cardinal angle. Valves nearly equal. Subcentral- 
tubercle well-developed, eye-tubercle rounded, distinct and lies below the anterior 
cardinal angle. Surface ornamentation consists of short spines and/or papillae 
superimposed on reticulations. A distinct ventral ridge, diagnostic of the genus, 



64 EARLY TERTIARY OSTRACODA 

over-reaches the ventral margin in lateral view and is spinose posteriorly. It 
extends from the anteroventral corner to the posterior third. The posterodorsal 
process is projecting and blade-like (present in most specimens). Anterior and 
posterior marginal rims distinct. Anterior margin finely denticulate, posteroventral 
margin ornamented with 6-7 short spines or papillae. Internal features not seen. 

Dimensions (mm). 

L H W 

Io. 4347 Carapace (holotype) 0-54 0-33 0-44 

Comparison. Phalcocy there sentosa sp. nov. is similar and perhaps ancestral to the 
present species. These two, however, can be separated easily due to the fact that 
P. sentosa is strongly dimorphic and has a less well-developed ventral ridge and a 
posterodorsal process. 

Remarks. This species has so far only been recorded from one horizon of the 
Upper Chocolate Clays of the Zao River section. Sexual dimorphism has not been 
observed in this species. 



Phalcocythere sp., cf. P. spinosa 

(Plate 33, figs. 3-6, 9-11) 
Figured specimens. Io. 4230 — Io. 4232. 



Material. Five specimens from the locality and horizon below (other specimens 
in the collections of the British Petroleum Co. Ltd., under registration no. FCRM 
1648). GSPBM2580. 

Locality. Lindi survey, 10-50 ft. above shore at Kitunga, Tanzania. 

Horizon. Upper Eocene. 

Description. Sexual dimorphism rather marked ; the females are higher and 
wider than the males. Carapace subrectangular to subquadrate in lateral outline. 
Dorsal margin irregular in lateral view due to ornamentation ; ventral margin almost 
straight ; anterior margin broadly rounded ; posterodorsal margin very slightly 
concave ; posterior extremity rounded. Right valve over-reaches the left slightly 
at the anterior margin. Anterior and posterior cardinal angles well-developed 
particularly in right valve. Greatest length below mid-point, greatest height at 
anterior cardinal angle and greatest width in the posterior third. Subcentral-tubercle 
distinct. Eye-tubercle rounded and prominent. Anterior and posterior marginal 
rims distinct. Surface ornamentation consists of reticulations with superimposed 
spines ; ventral ridge prominent, posteriorly alate, ending abruptly in the posterior 
third ; posterodorsal process prominent and blade-like, standing out in lateral and 
dorsal views. Anterior margin ornamented with numerous very short spines ; 
posterior with six larger spines. Radial pore canals not discernible. Duplicature 
moderately wide. Selvage strong — marginal in left valve but in right valve it is in 
the outer third. Right valve with a deep flange groove. Muscle scars are in a 
vertical row of four adductors, and frontal scars not seen. Hinge holamphidont 
with the details of each element as follows : 



FROM WEST PAKISTAN 



65 



Element 
Anterior 



Anteromedian 
Posteromedian 

Posterior 



Dimensions (mm). 



Left valve 

Deep rounded socket. 



Conical projecting tooth. 
Denticulate bar. 

Elongate groove, 
presumably deep (filled 
in with matrix). 



Right valve 

Projecting conical tooth. 

Eye-socket opens below 

and slightly anterior to 

this tooth. 

Socket opening into groove. 

Shallow locellate groove 

narrowing towards posterior. 

Subpessular tooth, higher 

on the posterior side. 



L 

o-55 
0-56 



H 

0-32 

o-34 



W 
0-30 

o-34 



Io. 4230 Carapace male 

Io. 4231 Carapace female 

Io. 4232 Right valve female (broken) — Jw, 0*17 

Comparison. Phalcocythere spinosa sp. nov. closely approaches the present form 
but is smaller, has a less reticulate and spinose surface and a more concave postero- 
dorsal slope. Phalcocythere retispinata sp. nov. is much larger, has a slightly convex 
dorsal margin particularly in the female dimorph, and the carapace tapers towards 
the posterior. 

Remarks. The specimens studied were made available through the kindness of 
Dr. F. E. Eames, lately Chief Palaeontologist of the British Petroleum Co. Ltd. 
These specimens may represent a distinct sub-species of P. spinosa. 



Genus QUADRACYTHERE Hornibrook 1952 
Type species. Cythere truncula Brady 1898. 



Subgenus HORNIBROOKELLA Moos 1965 
Type species. Cythere anna Lienenklaus 1894. 

Quadracythere (Hornibrookella) platybomus sp. nov. 
(Plate 33, figs. 14, 15, 18, 19). 

Derivation of name. Greek platys, broad -f- bomos, bottom ; with reference to 
the expanded venter. 

Diagnosis. Carapace with expanded venter, subrectangular to subquadrate in 
lateral outline. 

Holotype. Io. 4351, a male carapace (PI. 33, figs. 14, 18). 

Paratype. Io. 4300. 

Material. Nine specimens from the locality below from two horizons (sample 
nos. 460-i and 460-0) . GSP BM 2581-2. 



L 


H 


W 


o-57 


0-32 


0-24 


o-57 


o-34 


0-29 



66 EARLY TERTIARY OSTRACODA 

Type locality. Sor Range section. 

Type horizon. Upper Palaeocene, sample no. 460-i. 

Description. Carapace subrectangular in the male dimorph and subquadrate in 
the female. Sexual dimorphism rather apparent ; the females are higher and wider 
than the males. Carapace compressed in the posterior region. Anterior margin 
broadly rounded, posterodorsal slope very slightly curved, posterior almost rounded, 
post ero ventral margin slightly curved. The ornamentation over-reaches the dorsal 
margin giving a jagged appearance, ventral margin almost straight in the male but 
slightly curved in the female. Left valve very slightly over-reaches the right at the 
posterodorsal slope and at the anterior cardinal angle. In dorsal view the greatest 
width is situated anterior to the middle. Subcentral-tubercle prominent, eye-tubercle 
distinct. A marginal rim runs around the anterior, ventral and posterior margins. 
It is upraised around the anterior but less elevated along the venter and around the 
posterior end. Surface reticulate with a well-marked ventral ridge giving rise to an 
expanded venter. At the posterodorsal corner a small horn-like projecting ridge is 
present. Anterior margin ornamented by small, numerous denticles (20-25 in 
number) but the posterior has only a few denticles. 

Dimensions (mm). 

Io. 4351 Carapace male (holotype) 
Io. 4300 Carapace female 

Comparison. Quadracythere {Hornibrookella) directa sp. nov. is larger, has a less 
well-developed subcentral-tubercle and lacks an expanded venter. 

Remarks. The preservation of the material prevents a description of the internal 
characters. So far this species is only known from the Upper Palaeocene of the Sor 
Range section. 

Quadracythere (Hornibrookella) directa sp. nov. 
(Plate 33, figs. 16, 17 ; Plate 34, figs. I, 2) 

Derivation of name. Latin directus, rectangular ; with reference to the outline 
in lateral view. 

Diagnosis. In lateral view carapace subrectangular with protruding anterior and 
posterior cardinal angles. Surface ornamentation consists of reticulation with an 
oblique ventral ridge sloping upward towards posterior and a short horn-like ridge at 
posterodorsal corner. Sexual dimorphism pronounced. 

Holotype. Io. 4350, a female carapace (PL 33, figs. 17 ; PI. 34, fig.2). 

Paratype. Io. 4301. 

Material. 96 specimens from the type locality from four horizons (sample 
nos. 3184, 3192, 3402 and 3403) . GSP BM 2583-4. 

Type locality. Rakhi Nala section. 

Type horizon. Green and Nodular Shales, sample no. 3403. 



FROM WEST PAKISTAN 67 

Description. Sexual dimorphy rather apparent ; the females are shorter, higher 
and wider than the males. Carapace subrectangular in side view with the greatest 
height at the anterior cardinal angle and the greatest length below the middle. 
Anterior margin broadly and evenly rounded, posterodorsal slope very slightly 
concave, posterior extremity subtriangular, postero ventral margin almost straight. 
Dorsal margin very slightly undulating, venter slightly incurved in front of the middle. 
Posterior portion of carapace compressed. Anterior marginal rim high continuing 
along the venter and around the posterior end as a somewhat less elevated rim. 
Anterior margin set with numerous small and delicate denticles, posterior with a few 
denticles. Anterior and posterior cardinal angles protruding. Left valve over- 
reaches the right valve slightly at the anterior cardinal angle and posterodorsal 
slope. In dorsal view the greatest width is situated almost in the middle of the 
carapace. Eye-tubercle distinct. Subcentral-tubercle more or less distinct. Surface 
reticulate with a ventral ridge, which slopes slightly upwards towards the posterior. 
A short curved, hornlike ridge at the posterodorsal corner is present (better seen in 
dorsal view). Internal details not known. 

Dimensions (mm). 

L H W 

Io. 4301 Carapace male 0-68 0-35 0-27 

Io. 4350 Carapace female (holotype) 0-63 0-37 0-29 

Comparison. Quadracythere (Hornibrookella) subquadra sp. nov. is subquadrate 
in lateral outline, has deeper reticulations and a better developed subcentral-tubercle. 

Quadracythere (Hornibrookella) arcana (Lubimova and Guha) 

(Plate 34, figs. 3-5) 

i960 Cythereis arcanus (sic, recte Cythereis arcana) Lubimova and Guha, p. 33, pi. 3, fig. ia-b. 

Diagnosis. Carapace with distinct caudal process. Surface coarsely reticulate 
with superimposed longitudinal lineations in posterior half of carapace. 

Figured specimen. Io. 3142. 

Material. Two specimens from the locality and horizon below. 

Locality. Rakhi Nala section. 

Horizon. Lower Chocolate Clays, sample no. 3499. 

Description. Carapace thick-shelled, subquadrate in lateral view. Anterior 
margin broadly rounded, posterior with a pronounced caudal process. Dorsal margin 
slightly concave behind the round and protruding anterior cardinal angle, particularly 
in the right valve. Ventral margin almost straight. Greatest height at the anterior 
cardinal angle and greatest length below the middle. Left valve slightly over- 
reaches the right in the region of the anterior cardinal angle and posterodorsal slope. 
Eye-tubercle rounded and distinct, subcentral-tubercle well-developed. Surface 
ornamentation consists of coarse reticulations with superimposed longitudinal 
lineations in the posterior half of the carapace. The ventral ridge is slightly concave 
downwards culminating in an ala posteriorly. A short ridge at the posterodorsal 



68 EARLY TERTIARY OSTRACODA 

corner meets the dorsal margin at an angle (better seen in dorsal view) and ends as an 
ala at the posterior. A marginal rim runs round the anterior, along the venter and 
round the posterior margin. 

Dimensions (mm). 

L H W 

Io. 3142 Carapace 0-54 0-32 0-32 

Remarks. Topotype material was not available for study, and it is, therefore, 
difficult to determine whether or not the Rakhi Nala specimens are conspecific with 
those from the type locality in Kutch. 

Quadracythere (Hornibrookella) subquadra sp. nov. 

(Plate 34, figs. 6-1 1) 

Derivation of name. Latin subquadrus, almost square ; with reference to the 
outline in lateral view. 

Diagnosis. Carapace subquadrate with dorsal and ventral margins almost 
straight and subparallel. Surface strongly and coarsely reticulate. Sexual dimorphy 
moderate. 

Holotype. Io. 4352, a female carapace (PI. 34, figs, 7, 10, 11). 

Paratype. Io. 4302. 

Material. 41 specimens from the locality below from one horizon (sample 
no. 24161). GSP BM 2585-6. 

Type locality. Zao River section. 

Type horizon. Upper Chocolate Clays, sample no. 24161. 

Description. Carapace subquadrate in lateral outline with a short caudal process. 
Anterior margin broadly rounded, posterodorsal slope slightly concave, posterior 
extremity almost straight, posteroventral margin curved. Dorsal and ventral 
margins nearly straight and sub-parallel. Greatest height at the anterior cardinal 
angle, greatest length below the mid-point. In dorsal view the greatest width is 
situated in front of the middle. Anterior cardinal angle rounded, posterior cardinal 
angle well-developed. Left valve over-reaches the right valve slightly in the region 
of the posterodorsal slope and the anterior cardinal angle. Sub central-tubercle 
prominent, eye-tubercle rounded and distinct. Surface coarsely and deeply reticulate. 
There is a distinct ventral ridge at some distance from the venter and a short 
curved hornlike ridge at the posterodorsal corner. Anterior marginal rim prom- 
inent continuing along the venter and around the posterior margin as a less 
prominent rim. Anterior margin ornamented with numerous denticles. 

Sexual dimorphism moderate ; the presumed females are wider than the males. 

Dimensions (mm). 

L H W 

Io. 4302 Carapace male o-66 0-40 0-32 

Io. 4352 Carapace female (holotype) 0-67 0-42 0-34 



FROM WEST PAKISTAN 69 

Comparison. Quadracythere (Hornibrookella) arcana (i960) is smaller, has a well- 
developed caudal process, superimposed longitudinal lineations and a ventral ridge 
slightly curved downward. Quadracythere (Hornibrookella) platybomus sp. nov. is 
also smaller, has a different lateral outline, less deep reticulations and an expanded 
venter. 

Remarks. Quadracythere (Hornibrookella) subquadra sp. nov. commonly occurs 
at one horizon (sample no. 24161) of the Upper Chocolate Clays in the Zao River 
section associated with Echinocythereis multibullata sp. nov. and Phalcocythere spinosa 
sp. nov. 

Quadracythere (Hornibrookella) sp.A 
(Plate 34, figs. 12-14) 

Figured specimen. Io. 3143. 

Material. Only one specimen from the locality and horizon below. 

Locality. Zao River section. 

Horizon. Upper Chocolate Clays, sample no. 24148. 

Description. Carapace subquadrate in side view. Dorsal and ventral margins 
almost straight, anterior margin broadly and obliquely rounded, posterodorsal 
margin slightly concave, posteroventral margin rounded. Greatest length lies below 
the middle, greatest height at the anterior cardinal angle. In dorsal view the great- 
est width lies anterior to the middle. Valves almost equal. Eye-tubercle distinct, 
rounded. Subcentral-tubercle distinct. Surface coarsely and deeply reticulate. 
Reticulae are somewhat concentrically arranged around the subcentral-tubercle. 
Dorsal ridge present but not well-defined, ventral ridge more or less distinct. A low 
marginal rim runs around the anterior and posterior margins. Anterior and postero- 
ventral margins denticulate. Internal characters not observed. 

Dimensions (mm). 

L H w 

Io. 3143 Carapace 0-93 0-54 0-56 

Comparison. This is similar to Quadracythere (Hornibrookella) subquadra sp. nov. 
but is much larger, has coarser and deeper reticulations more or less arranged in a 
concentric pattern around the subcentral-tubercle. In addition, these two species 
differ markedly in their posterior outline. 

Genus STIGMATOCYTHERE nov. 

Derivation of name. Greek stigma, mark ; with reference to the ornamentation 
-\-cythere. 

Diagnosis. Highly ornamented Trachyleberididae in which two ridges spring 
from the eye-tubercle, one to form a high anterior marginal rim, the other curving 
sharply round to join the subcentral-tubercle. 

Type species. Stigmatocythere obliqua sp. nov. 



70 EARLY TERTIARY OSTRACODA 

Description. Carapace subrectangular in lateral outline. Sexual dimorphy 
apparent ; the males are longer, less high and less wide than the females. Left valve 
slightly over-reaches the right in the region of the anterior cardinal angle and at the 
posterodorsal slope. Subcentral node and eye-tubercle distinct. Surface reticu- 
late, spiny, or a combination of reticulations and spines or with only one to three 
longitudinal ridges or lines of ornamentation. The dorsal ridge or line when 
developed may be straight or arched convexly upwards. A strongly curved ridge, 
diagnostic of the genus, runs from the eye-tubercle to the anterodorsal corner of the 
subcentral complex and this may be continued posteriorly either as a ridge or a line 
of tubercles. The anterior marginal rim also springs from the eye-tubercle and is 
more or less elevated in the anterior region, continuing as a less elevated rim round 
the venter and posterior margins. A ventral ridge or line of tubercles diverges 
posteriorly from the ventral marginal rim. Anterior and posterior margins spinose. 
Normal pore canals simple, medium, some 60 in the female left valve. Radial pore 
canals simple, straight, irregularly spaced, some crossing one another, 24-26 anteriorly. 
Inner margin and line of concrescence coincide. Anterior duplicature moderately 
wide. Selvage well-marked in both valves, submarginal in the left valve but almost 
in the outer third of the duplicature in right valve. In right valve a well-developed 
flange groove is present along the ventral margin and around the anterior margin. 
Muscle scars consist of four adductor scars in an almost vertical column with an oval 
frontal scar. Hinge holamphidont ; right valve hinge with a strongly projecting 
anterior tooth followed by anteromedian socket, posteromedian locellate groove 
present or reduced to a narrow shelf, a posterior tooth, projecting reniform orpessular. 
Left valve hinge with anterior and posterior sockets, a conical anteromedian tooth and 
a posteromedian denticulate or almost smooth bar. 

Comparison. Stigmatocythere differs from the genus Gyrocy there in the arrange- 
ment of the longitudinal ridges and by having a strongly curved ridge connecting the 
eye-tubercle and the subcentral-tubercle. The anterior marginal rim is less evident 
in Gyrocythere while it is well developed in Stigmatocythere. Costa has three or four 
continuous longitudinal ridges, the median or second of which has a characteristic 
posterior termination absent in Stigmatocythere and lacks the anterior connection 
to the eye-tubercle present in Stigmatocythere. Bradley a has only dorsal and ventral 
ridges. Carinocythereis Ruggieri 1956 has a V-shaped frontal scar and small vesti- 
bules, characters not found in Stigmatocythere. 

Remarks. Stigmatocythere is so far only known from the Middle and Upper 
Eocene of the Sulaiman Range. 

Stigmatocythere obliqua sp. nov. 
(Plate 35, figs. 1-10 ; Plate 36, figs. 1-2) 

Derivation of name. Latin obliqua, oblique ; with reference to the ventral 
ridge. 

Diagnosis. A strongly reticulate species of Stigmatocythere with three well- 
developed longitudinal ridges including an oblique ventral ridge. 



FROM WEST PAKISTAN 71 

Holotype. Io. 4355, a female carapace (Plate 35, figs. 2, 5, 6 ; Plate 36, fig. 2). 

Paratypes. Io. 4303 + Io. 3147 + Io. 3148 + Io. 3149. 

Material. Over 1400 specimens from the Rakhi Nala section from 17 horizons 
(sample nos. 3448, 3451 to 3454, 3456, 3457, 3460 to 3467, 3470 and 3473). 470 
specimens from the Zao River section from two horizons (sample nos. 24107 and 
241 10). Approximately 600 specimens from the Shpalai Khwara section from three 
horizons (sample nos. 24681, 24683 and 24686). GSP BM 2587-8. 

Type locality. Rakhi Nala section. 

Type horizon. Shales with Alabaster, sample no. 24173. 

Description. Carapace subrectangular in lateral view. Sexual dimorphism 
rather pronounced ; the females are shorter, higher and wider than the males. 
Anterior margin broadly and obliquely rounded, posterior nearly straight. Dorsal 
margin almost intricate because of the over-reaching of the dorsal ridge, venter 
slightly incurved in front of the middle. Valves almost equal except that the left 
valve over-reaches the right in the region of the anterior cardinal angle and along the 
posterodorsal corner. Eye-tubercle and subcentral-tubercle distinct. Shell surface 
strongly reticulate. Three longitudinal ridges present ; the dorsal ridge starts 
almost above the subcentral node and is arched convexly upwards ; the median ridge 
commences from the eye-tubercle, curves sharply round to join anterodorsal corner 
of the subcentral complex and continues posteriorly ; the ventral ridge slopes 
obliquely upwards towards the posterior. The reticulations in the mid-posterior 
region of the carapace show a concentric pattern, although it is not always present. 
A high anterior marginal rim commences from the eye-tubercle continuing as a less 
high rim round the venter and posterior. Anterior and posterior short marginal 
spines present, 18-20 anteriorly. Normal pore canals simple, some 60 in the female 
left valve. 24-25 anterior radial pore canals, simple straight, irregularly spaced, few 
crossing one another, mostly terminating in marginal spines. Inner-margin and line 
of concrescence coincide. Anterior duplicature 0-050 mm. wide in the female left valve. 
Selvage strong in both valves, subperipheral in left valve but in right valve it lies 
in the outer third of the duplicature. Right valve with deep anterior and ventral 
flange grooves. Muscle scar pattern consists of four adductor scars in a vertical row 
with an oval frontal scar. Hinge holamphidont, the details are as follows : 



Element 


Left valve 


Right valve 


Anterior 


Socket confluent with 


Strongly projecting sub- 




ocular sinus. 


conical or subpessular tooth 
with a tendency for the 
anterior profile in dorsal 
view to appear concave. 
The ocular sinus lies 
distally beyond this and 
opens to the interior below 
and in front of it. 



72 



EARLY TERTIARY OSTRACODA 



Anteromedian 



Posteromedian 



Posterior 



Dimensions (mm). 



Conical tooth with 
straight anterior in 
dorsal view. 
Denticulate bar. 



Deep socket, slightly 
elongate, open in centre. 



Deep socket. 



Locellate shelf, only 
detectable in best pre- 
served specimens. 
Pessular tooth, tending 
towards reniform in some 



specimens. 




L 


H 


w 


o-6i 


0-30 


0-29 


o-54 


o-33 


0-29 


0-52 


o-34 


— 


o-54 


0-32 


— 


o-54 


o-34 


— 


o-5i 


0-29 


— 



Io. 4303 Carapace male 

I°- 4355 Carapace female (holotype) 

Io. 3149 Left valve female 

Io. 3148 Right valve female 

Io. 3149 Left valve female 

Io. 3146 Right valve female 

Comparison. This species is perhaps ancestral to Stigmatocy there portentum sp. 
nov. which it resembles very closely, but differs in being smaller, having deeper 
reticulations and less prominent subcentral-tubercle. 

Remarks. The present species occurs abundantly in the Shales with Alabaster 
of the Rakhi Nala, Zao River and Shpalai Khwara sections and seems to be restricted 
to this formation. It is very likely that this species will prove to be a valuable 
horizon marker in the region. 

The longitudinal ridges in some of the specimens from the upper few horizons of the 
Rakhi Nala section are exaggerated and in some the dorsal and ventral ridges 
posteriorly terminate in spines. This is regarded here as specific variation. 

Stigmatocy there portentum sp. nov. 
(Plate 36, figs. 3-6, 10) 

Derivation of name. Latin portentum, omen or sign ; with reference to the 
diagnostic ornamentation. 

Diagnosis. A large, reticulate species of the genus Stigmatocy there with three 
distinct longitudinal ridges, prominent subcentral-tubercle. 

Holotype. Io. 4357, a male carapace (PI. 36, figs. 3-6). 
Paratypes. Io. 3144 + Io. 3145. 

Material. Eight specimens from the locality below from two horizons (sample 
nos. 3498 and 3499). GSP BM 2551. 
Type locality. Rakhi Nala section. 
Type horizon. Lower Chocolate Clays, sample no. 3498. 

Description. Carapace subrectangular in side view with the greatest height at 
the anterior cardinal angle and the greatest length above mid-point. Anterior 



FROM WEST PAKISTAN 73 

margin broadly rounded, posterior truncated. Dorsal margin straight, but looks 
irregular in lateral view because of over-reaching of the dorsal ridge ; ventral margin 
almost straight. Anterior and posterior cardinal angles well-developed particularly 
in the left valve. Left valve slightly over-reaches the right at the anterior cardinal 
angle and along the posterodorsal slope. Eye-tubercle distinct and rounded. Sub- 
central-tubercle prominent. Surface reticulate with three longitudinal ridges. Dorsal 
ridge wavy and convex upwards, it begins above the subcentral-tubercle and in the 
posterodorsal region, curves sharply down to meet the median ridge. A strongly 
curved ridge runs from the eye-tubercle to the subcentral-tubercle, continuing 
posteriorly as a median ridge. Ventral ridge commences above the anteroventral 
corner and is slightly convex downwards. There is a short, curved ridge on the 
ventral side of the subcentral-tubercle running towards the anterior end. A marginal 
rim runs along the anterior, ventral and posterior margins. It is high on the anterior 
but less high along the venter and posterior. Anterior ornamented with short, 
numerous spines. There is a large posteroventral spine. Radial pore canals simple, 
more or less straight, some crossing one another, few seem to bifurcate, some 25 
anteriorly. Inner margin and line of concrescence coincide ; no vestibule. Duplicature 
of moderate width with a well-marked selvage. Hinge holamphidont with a pro- 
jecting conical anterior tooth in the right valve. 

Dimensions (mm). 

Io. 4357 Carapace male (holotype) 
Io. 3144 Right valve (broken) 
Io. 3145 Carapace (juvenile) 

Comparison. This species has already been 
obliqua sp. nov. 

Remarks. S. portentum is a very rare ostracod and has so far only been found in 
the uppermost beds of the Lower Chocolate Clays of the Rakhi Nala section. 

Stigmatocythere calia sp. nov. 
(Plate 36, figs. 7-9 ; Plate 37, figs. 1, 3) 

Derivation of name. Greek, kalia, bird's nest ; from a fancied appearance of 
the ornamentation in lateral view. 

Diagnosis. A non-reticulate Stigmatocythere with straight posterior, high 
anterior marginal rim, prominent and projecting subcentral-tubercle, dorsal and 
ventral lines of ornamentation, posteroventral ridge, almost straight. 

Holotype. Io. 4353, a female carapace (PI. 36, figs, 8, 9 ; PI. 37, figs. 1, 3). 

Paratype. Io. 4304. 

Material. 15 specimens from the locality below from five horizons (sample 
nos. 24148, 24150 to 24153). GSP. BM. 2589. 

Type locality. Zao River section. 

Type horizon. Upper Chocolate Clays, sample no. 24151. 



L 


H 


W 


0-71 


o-37 


0-32 


— 


o-37 


— 


o-59 


o-35 


0-29 


compared 


with 


Stigmatocythere 



74 EARLY TERTIARY OSTRACODA 

Description. Sexual dimorphism distinct ; the males are more elongate than 
the females. Carapace subrectangular in lateral outline. Dorsal margin almost 
straight but appears undulating in side view due to the over-reaching of the dorsal 
line of ornamentation, ventral margin nearly straight. Anterior margin broadly 
and evenly rounded, posterior straight, posterodorsal slope almost straight. Left 
valve slightly over-reaches the right valve in the anterodorsal and posterodorsal 
corners ; otherwise the two valves are equal. Eye-tubercle distinct, rounded and 
polished. Subcentral-tubercle prominent and projecting particularly in dorsal and 
ventral views. Dorsal line of ornamentation consists of three nodes including a large 
subangular posterodorsal node which extends vertically down for a short distance. 
Ventral line of ornamentation consists of two nodes but in some specimens it is just a 
short ridge. A projecting, almost vertical postero ventral ridge runs from behind the 
ventral line of ornamentation to a point which is slightly above the mid-line. A 
curved ridge diagnostic of the genus runs from the eye-tubercle to the subcentral- 
tubercle ; it is not well-marked. The subcentral-tubercle has two faint, short, 
curved ridges on its ventral side, one to the anterior and one to the posterior. Anterior 
marginal rim high, extending along the ventral and posterior margins as a less high 
rim. Anterior margin set with numerous short spines, concealed in lateral view by 
the elevated anterior marginal rim. There is one short posterodorsal marginal spine 
and one short posteroventral marginal spine. Internal details not determinable. 

Dimensions (mm). 

L H W 

Io. 4304 Right valve male o-6i 0-34 — 

I°- 4353 Carapace female (holotype) 0-56 0-36 0-32 

Stigmatocythere delineata sp. nov. 
(Plate 37, figs. 2, 4-10) 

Derivation of name. Latin delineata, outlined ; from the resemblance of the 
ornamentation to sketch map. 

Diagnosis. A species of the genus Stigmatocythere with a large hexagon formed of 
ridges in the posteromedian region, dorsal ridge broken in the middle and extending 
vertically below in the posterodorsal region. 

Holotype. Io. 4356, a female carapace (PL 37, figs. 7-10). 

Paratype. Io. 4305. 

Material. Six specimens from the type locality from two horizons (sample 
nos. 24154 and 24155). GSP BM 2590-91. 

Type locality. Zao River section. 

Type horizon. Upper Chocolate Clays, sample no. 24154. 

Description. Sexual dimorphism apparent ; the males are proportionally 
longer than the females. Carapace subrectangular in side view. Dorsal margin 
slightly concave, ventral margin almost straight, anterior margin broadly and evenly 
rounded, posterodorsal slope and posteroventral margin nearly straight. Greatest 



FROM WEST PAKISTAN 75 

height lies at the anterior cardinal angle, greatest length above the mid-point and 
greatest width in the posterior third. Anterior and posterior cardinal angles pro- 
jecting particularly in the left valve. Left valve slightly over-reaches the right valve 
in the region of the anterodorsal corner and posterodorsal slope. Subcentral-tubercle 
and eye-tubercle distinct. The most prominent part of the ornamentation is a large 
slightly irregular hexagon formed of ridges just to the posterior of centre. Other 
short ridges, mostly running outwards, join this hexagon at its corners. A sharply 
curved ridge characteristic of the genus connects the eye-tubercle and the subcentral 
tubercle. Dorsal ridge is broken in the middle and in the posterodorsal region it 
extends vertically below to a point slightly above mid-line. The ventral ridge runs 
at a slightly oblique angle towards the posterior end, its posterior portion forming the 
ventral part of the hexagon. A high marginal rim runs on around the anterior margin 
and continues along the ventral and posterior margins as a less high rim. Anterior 
margin denticulate, postero ventral corner ornamented with a short spine. Dup- 
licate e of moderate width with a strong selvage. Hinge holamphidont. 

Dimensions (mm). 

L H W 

Io. 4305 Carapace male o-6i 0-34 0-29 

Io. 4356 Carapace female (holotype) 0-56 0-34 0-29 

Comparison. It is easy to separate S. delineata from other described species of 
the genus Stigmatocy there due to its characteristic surface ornamentation particularly 
the large hexagon formed of ridges just to the posterior of centre. 



Stigmatocy there lumaria sp. nov. 
(Plate 37, figs. 11 ; Plate 38, figs. 1-10 ; Plate 39, figs. 1-8, 11) 
Derivation of name. Latin lumarius, thorny. 

Diagnosis. A species of Stigmatocythere with a prominent and bilobate subcentral- 
tubercle. Surface tuberculate or combination of reticulations and tubercles. Three 
large, projecting tubercles in the mid-dorsal region. 

Holotype. Io. 4354, a male carapace (PI. 38, figs. 1, 5, 8). 

Paratypes. Io. 4306-7 + Io. 3150-4. 

Material. Approximately 340 specimens from the Rakhi Nala section from 21 
horizons (sample nos. 3621, 3624 to 3628, 3630, 3640 to 3642, 3645 to 3652, 3658, 
3662 and 3663). 86 specimens from the Zao River section from 11 horizons (sample 
nos. 24156, 24157, 24159, 24170, 24173 to 24176, 24180, 24187 and 24193). GSP BM 
2592-94. 

Type locality. Rakhi Nala section. 

Type horizon. Upper Chocolate Clays, sample no. 3642. 

Description. Sexual dimorphism rather pronounced ; the females are shorter 
and higher than the males. Carapace subrect angular in lateral view. Anterior 
margin broadly rounded, posteroventral margin and posterior extremity more or 



76 



EARLY TERTIARY OSTRACODA 



less rounded, posterodorsal slope very slightly concave. Dorsal margin straight but 
appears intricate due to surface ornamentation ; ventral margin slightly concave in 
front of the middle, particularly in right valve. Greatest height lies in the anterior 
third, greatest length passes above mid-line. Anterior and posterior cardinal angles 
well-marked. Valves almost equal. Eye-tubercle distinct and rounded. Subcentral- 
tubercle prominent and bilobate. Surface ornamentation consists of either tubercles 
or a combination of reticulations and tubercles. In some cases tubercles become 
almost spinose. There are three tubercles in the mid-dorsal region and in most 
specimens these project beyond the dorsal margin in lateral outline. The eye- 
tubercle is joined to the subcentral-tubercle, by a sharply curved ridge, diagnostic of 
the genus. The ventral side of the subcentral-tubercle has two weak, short, curved 
ridges ; one extends towards the anterior and the other towards the posterior end. 
Anterior marginal rim well-marked, ventral and posterior marginal rims less well- 
marked. Anterior and posterior margins decorated by short, numerous spines. 
Posterior has several short spines and two large, somewhat blunt spines, one in the 
posteroventral corner and the other in the posterodorsal corner. Radial pore canals, 
simple, almost straight, irregularly spaced, some crossing one another, 25-26 
anteriorly. Line of concrescence and inner margin coincide. Anterior dupiicature 
moderately wide, one-twelfth of the entire length of the valve. Selvage pronounced, 
in right valve it lies in the outer third of the dupiicature but in left valve it is sub- 
marginal. Right valve with deep ventral and anterior flange grooves. Adductor 
scars in a vertical column of four. Frontal scar not clearly seen but appears to be 
oval in shape. Hinge holamphidont with the following details : 

Right valve 

Strongly projecting conical 

tooth. Ocular sinus lies 

below and slightly 

anterior to it. 

Deep socket bounded on 

venter and opening into 

posteromedian groove. 

Locellate groove. 
Tooth more or less rounded 
in lateral view but 
pessular in dorsal view. 

Comparison. Stigmatocythere portentum sp. nov. is larger, than the present 
species, has three distinct longitudinal ridges, lacks a tuberculate surface and bilobate 
subcentral-tubercle. Stigmatocythere calia sp. nov. is probably ancestral to 
S. lumaria but has a vertical posteroventral ridge and more elevated anterior 
marginal rim. Further, it lacks a tuberculate surface and bilobate subcentral- 
tubercle. 

This species can be separated into two morphotypes, although it is rather difficult 
to maintain a distinction between them because of many intermediate forms : 



Element 


Left valve 


Anterior 


Socket bounded on all 




sides, ocular sinus 




opening into it. 


Anteromedian 


Subconical tooth with 




straight anterior and 




convex posterior in 




dorsal view. 


Posteromedian 


Denticulate bar. 


Posterior 


Deep socket open in 




venter. 



L 


H 


w 


0-67 


o-37 


o-34 


0-63 


o-37 


— ■ 


o-59 


0-32 


— 


o-68 


o-37 


— 


o-59 


0-40 


— 


o-6o 


o-37 


— 



FROM WEST PAKISTAN 77 

MORPHOTYPE A 

(Plate 37, figs. 11 ; Plate 38, figs. 1-10 ; Plate 39, fig. 11) 

This has a tuberculate surface. Tubercles vary in size and number. Some have 
few large tubercles with a tendency to become spinose and in others tubercles are 
small and rounded. 

Dimensions (mm). 

Io. 4354 Carapace male (holotype) 

Io. 4307 Right valve female 

Io. 4306 Left valve male (juvenile) 

Io. 3151 Right valve male 

Io. 3152 Left valve female 

Io. 3154 Right valve female 

Morphotype B 
(Plate 39. figs. 1-8) 

This is very similar to Morphotype A, but has a surface ornamentation which is a 
combination of reticulations and tubercles. 

Dimensions (mm). 

Io. 3150 Carapace male 
Io. 3153 Carapace female 

Remarks. This species has been described as Genus and sp. indet.G. by I. G. 
Sohn in his paper on Lower Tertiary ostracods from Western Pakistan, still in press. 



Genus TRACHYLEBERIS Brady 1898 
Type species. Cythere scabrocuneata Brady 1880. 

Subgenus TRACHYLEBERIS sensu stricto 

Trachyleberis (Trachyleberis) lobuculus sp. nov. 

(Plate 39, figs, 9, 10 ; Plate 40, figs, i, 3) 

Derivation of name. Latin lobus, lobe + oculus, eye ; with reference to the 
lobate eye-tubercle. 

Diagnosis. A species of the subgenus Trachyleberis in which eye-tubercle is 
lobate, surface ornamented with tubercles, posterior cardinal angle well-marked in 
left valve. 

Holotype. Io. 4364, a female carapace (PL 40, figs. 1, 3). 

Paratype. Io. 4308. 



L 


H 


w 


o-66 


o-37 


0-32 


0-62 


o-37 


0-31 



78 EARLY TERTIARY OSTRACODA 

Material. 287 specimens from the locality below from 49 horizons (sample 
nos. 3147, 3160, 3162, 3163, 3166, 3167, 3169 to 3171, 3173 to 3175, 3177 to 3180, 
3183 to 3193, 3197 to 3200, 3401 to 3404, 3407, 3409, 3410, 3415, 3417 to 3422, 3428, 
3429, 3434 and 3435) . GSP BM 2595-6. 

Type locality. Rakhi Nala section. 

Type horizon. Upper Rakhi Gaj Shales, sample no. 3166. 

Description. Carapace subrectangular in the male dimorph and sub-quadrate in 
the female. Sexual dimorphy apparent, the males being larger in proportion to the 
females. Dorsal and ventral margins subparallel (undulating in lateral view because 
of surface ornamentation) . Anterior margin broadly rounded, posterodorsal margin 
almost ' straight, posterior extremity somewhat rounded, posterodorsal margin 
curved. Greatest height at anterior cardinal angle and greatest length in the 
middle. Valves more or less equal. Eye-tubercle lobate and prominent situated just 
below a well-developed anterior cardinal angle. Posterior cardinal angle well- 
marked in the left valve, armed with a node or short spine pointing upwards. Sub- 
central-tubercle distinct. Both anterior and posterior margins ornamented with a 
double row of tubercles or very short spines. Surface tuberculate or nodose (oc- 
casionally tubercles or nodes develop into spines) . Anterior and posterior marginal 
rim more or less distinct. Hinge holamphidont : left valve with terminal sockets, 
postjacent conical tooth and median denticulate bar ; right valve hinge compliment- 
ary (anterior tooth being conical) . Duplicature of moderate width with a submarginal 
selvage. Other internal details not determinable. 

Dimensions (mm). 

L H W 

Io. 4308 Carapace male o-6i 0-34 0-24 

Io. 4364 Carapace female (holotype) 0-59 0-35 0-28 

Comparison. T. lobuculus is probably related to Cythereis spinellosa Lubimova 
and Guha (i960) but differs in having a lobate eye-tubercle and a different lateral 
outline and surface ornamentation. 

Remarks. Specimens of Cythereis spinellosa Lubimova and Guha were not 
available for comparison, but from the description and figure given by these authors 
it appears that the eye-tubercle in that particular species is not lobate. 

Trachyleberis (Trachyleberis) bimammillata sp. nov. 
(Plate 40, figs. 2, 4-11) 

Derivation of name. Latin bimammillata, two-breasted ; with reference to the 
split subcentral-tubercle. 

Diagnosis. A small species of the subgenus Trachyleberis in which subcentral- 
tubercle is divided into two horizontally disposed nodes and posterodorsal process 
consisting of two vertically arranged nodes. 

Holotype. Io. 4363, a male carapace (PI. 40, figs. 2, 8, 10). 

Paratypes. Io. 3155-9. 



FROM WEST PAKISTAN 



79 



Material. 42 specimens from the Rakhi Nala section from 5 horizons (sample 
nos. 3610, 3613 to 3615 and 3617). 7 specimens from the Zao River section from 
two horizons (sample nos. 24150 and 24152). GSP BM 2597. 

Type locality. Rakhi Nala section. 

Type Horizon. Upper Chocolate Clays, sample no. 3613. 

Description. Carapace subrectangular to subquadrate in lateral outline. 
Sexual dimorphism moderate ; the presumed males are longer and less high than the 
females. Dorsal and ventral margins straight and tapering towards the posterior. 
Anterior margin broadly rounded, posterodorsal slope very slightly concave, posterior 
extremity rounded, posterodorsal margin somewhat rounded. Anterior, posterior 
and ventral margins decorated with a double row of short spines, but dorsal margin 
with only one row of very short spines (these in some specimens almost look like 
pustules). Greatest height at the anterior cardinal angle (which is obtuse and 
angular) and greatest length through the mid-point. In dorsal view the greatest 
width lies at the anterior node of the subcentral-tubercle. Valves almost equal. 
Eye-tubercle rounded and distinct. Subcentral-tubercle divided into two nodes, 
horizontally arranged, the anterior one being larger (spinose in some specimens). 
The posterodorsal process consists of two nodes (spines in some specimens), which 
are vertically disposed. In a few specimens a posteroventral node is also present. 
Surface ornamented with scattered tubercles and spines. Duplicative fairly wide. 
The selvage is subperipheral and well-developed in both valves. Radial pore canals 
not seen because of mineralization. The adductor muscle scars are in an oblique row 
of four at the posterior margin of the subcentral pit. The frontal scar is large and 
U-shaped and opens towards the anterodorsal corner. Hinge holamphidont with 
the following details : — 



Element 

Anterior 

Anteromedian 

Posteromedian 

Posterior 

Dimensions (mm). 



Left valve 
Socket. 

Subcorneal tooth. 
Denticulate ridge. 
Fairly deep socket. 



Right valve 

Projecting subcorneal tooth. 

Socket. 

Locellate groove. 

Tooth, subpessular in dorsal 

view. 



Io. 4363 Carapace male (holotype) 

Io. 3159 Carapace female 

Io. 3158 Left valve male (broken) 

Io. 3156 Left valve female 

I°- 3 I 55 Right valve female 

Io. 3160 Carapace male 

Io. 3157 Carapace female 

Comparison. This species can easily be distinguished from Trachyleberis (Trachy- 
leberis) lobuculus sp. nov. by its smaller size, slightly concave posterodorsal margin 
and split subcentral-tubercle. Further, Trachyleberis (Trachyleberis) bimammillata 



L 


H 


w 


0-52 


0-29 


0-22 


0-50 


0-29 


0-24 


— 


0-29 


— 


0-50 


0-29 


— 


0-49 


0-29 


— 


o-54 


0-29 


0-22 


0-49 


0-29 


0-24 



80 EARLY TERTIARY OSTRACODA 

has a posterodorsal process consisting of two nodes in a vertical row and lacks a 
lobate eye-tubercle. 



Subgenus ACANTHOCYTHEREIS Howe 1963 
Type species. Acanthocythereis araneosa Howe 1963. 

Trachyleberis (Acanthocythereis) procapsus sp. nov. 

(Plate 40, figs. 12, 13 ; Plate 41, figs. 1, 3, 4) 

Derivation of name. Latin procapsus, anterior cage ; with reference to the 
smooth walled area enclosed behind the anterior marginal rim. 

Diagnosis. Acanthocytheris in which a smooth walled area lies behind the anterior 
marginal rim, anterior and posterior platforms compressed. 

Holotype. Io. 4360, a male carapace (PI. 40, fig. 12 ; PL 41, figs, 1, 3). 

Paratype. Io. 3164. 

Material. Six specimens from the locality below from two horizons (sample 
nos. 460-j and 460-i) . GSP BM 2598. 

Type locality. Sor Range section. 

Type horizon. Upper Palaeocene, sample no. 460-j. 

Description. Sexual dimorphism apparent ; the males are longer in proportion 
to the females. Carapace elongate, subrectangular in lateral outline with dorsal and 
ventral margins almost straight, tapering towards the posterior. Anterior margin 
broadly rounded, posterior subtriangular. Anterior cardinal angle rounded. Left 
valve over-reaches the right very slightly at the posterodorsal margin. Greatest 
height through the anterior cardinal angle and greatest length through the mid- 
point. In dorsal view the greatest width is situated at the anterior third. Sub- 
central-tubercle distinct. Eye-tubercle rounded and distinct and lies at the anterior 
cardinal angle. Surface reticulate (reticulae joined by walls or pustules or papillae). 
Posterodorsal process consists of small more or less rounded protuberances. Anterior 
and posterior margins ornamented by a double row of short spines. Anterior and 
posterior marginal rims high with a smooth walled area behind. Internal details not 
known. 

Dimensions (mm). 

L H W 

Io. 4360 Carapace male (holotype) o-68 0-32 0-20 

Io. 3164 Carapace female 0-59 0-30 0-20 

Comparison. This species is distinguishable from Trachyleberis (Acanthocythereis) 
usitata sp. nov. by its deeper reticulation, more elevated marginal rims and spinose 
anterior and posterior margins. 

The present species has already been compared with Trachyleberis (Acanthocythereis) 
postcornis sp. nov. and Trachyleberis (Acanthocythereis) decoris sp. nov. 



FROM WEST PAKISTAN 81 

Remarks. T. (A.) procapsus has so far only been recovered from the Upper 
Palaeocene of the Sor Range section. 

Trachyleberis (Acanthocythereis) usitata sp. nov. 

(Plate 41, figs. 2, 5, 7) 

Derivation of name. Latin usitatus, usual. 

Diagnosis. Carapace tapering towards posterior. Subcentral-tubercle distinct. 
Surface reticulate with superimposed pustules and a posterodorsal process. 

Holotype. Io. 4362, a male carapace (PI. 41, fig. 2). 

Paratype. Io. 3161. 

Material. Five specimens from the Rakhi Nala section from four horizons 
(sample nos. 3111, 3130, 3132 and 3133). GSP BM 2599. 

Type locality. Rakhi Nala section. 

Type horizon. Gorge Beds, sample no. 3111. 

Description. Sexual dimorphy present ; the males are longer in proportion to 
the females. Carapace elongate, subrectangular, tapering towards the posterior. 
Anterior margin broadly rounded, posterior narrowly rounded. Dorsal and ventral 
margins almost straight. Greatest height at the anterior cardinal angle which is 
well-developed in the left valve. Greatest length passes through mid-point. Valves 
almost equal. In dorsal view greatest width lies in the anterior third (in the region 
of the subcentral-tubercle). Eye-tubercle rounded and distinct. Subcentral-tubercle 
fairly distinct. Anterior and posterior marginal rims sharply defined. Surface 
reticulate with pustules at reticulae intersections. A posterodorsal process in the 
form of more or less rounded tubercle of medium size present. A double row of 
pustules decorates anterior and posterior margins. Internal characters not known. 

Dimensions (mm). 

L H W 

Io. 4362 Carapace male (holotype) 0-63 0-32 — 

Io. 3161 Carapace female 0-59 0-32 0-22 

Comparison. This species shows some resemblance to Trachyleberis {Acantho- 
cythereis) decoris sp. nov. but is smaller, has marginal pustules rather than spines and 
carapace more tapering towards the posterior. Trachyleberis (Acanthocythereis) 
postcornis has a characteristic posterodorsal process, more high marginal rims and 
spinose anterior and posterior margins. 

Remarks. In some specimens the posterodorsal process is not well-developed. 

Trachyleberis (Acanthocythereis) pedigaster sp. nov. 

(Plate 41, figs. 6, 8) 

Derivation of name. Greek pedigaster, flat belly ; with reference to the ventral 
inflation. 

Diagnosis. A large species of the subgenus with ventral inflation. Carapace 
tapering towards posterior. Posterior margin subtriangular. 

F 



82 EARLY TERTIARY OSTRACODA 

Holotype. Io. 4358, a carapace. 

Material. Only one specimen from the locality and horizon below. 

Type locality. Rakhi Nala section. 

Type horizon. Lower Rakhi Gaj Shales, sample no. 3671. 

Description. Carapace large, elongate, tapering towards posterior and with 
ventral inflation. Anterior and posterior marginal platforms compressed. Dorsal 
and ventral margins almost straight, anterior margin broadly rounded, posterior 
subtriangular. Anterior and posterior cardinal angles well-developed particularly 
in the left valve. Left valve slightly larger than the right, which it over-reaches in 
the region of the anterodorsal corner and posterodorsal slope. Eye-tubercle rounded 
and distinct and lies just below the anterior cardinal angle. Subcentral-tubercle more 
or less distinct. Greatest height through the anterior cardinal angle, greatest length 
below mid-point and greatest width a little posterior to the middle. Surface 
ornamentation consists of reticulations with superimposed papillae. The postero- 
dorsal process consists of two almost rounded small tubercles (or papillae) joined 
together in the left valve and one small rounded tubercle in the right. Anterior and 
posterior marginal rims fairly distinct. Anterior and posterior margins ornamented 
with a double row of papillae. Internal details unknown. 

Dimensions (mm). 

L H W 

Io. 4358 Carapace (holotype) 1-02 0-51 — 

Comparison. There is no difficulty in separating T. (A.) pedigaster sp. nov. from 
other described species of the subgenus Acanthocythereis by its large carapace and 
subtriangular posterior. 

Trachyleberis (Acanthocythereis) postcornis sp. nov. 
(Plate 41, figs. 9, 10; PI. 42, figs. 1, 2, 7, 10) 

Derivation of name. Latin post, posterior + cornis, horned ; with reference to 
the posterodorsal process. 

Diagnosis. A species of the subgenus Acanthocythereis with distinct subcentral- 
tubercle and eye-tubercle. Surface reticulate with small superimposed spines. 
Posterodorsal process divided into two spines. 

Holotype. Io. 4361, a male carapace (PI. 42, figs. 1, 2, 7, 10). 

Paratypes. Io. 4309+3162-4. 

Material. 45 specimens from the locality below from two horizons (sample 
nos. 3498 and 3499) and 3 specimens from the Zao River section from two horizons 
(sample nos. 24131 and 24148). GSP BM 2600. 

Type locality. Rakhi Nala section. 

Type Horizon. Lower Chocolate Clays, sample no. 3499. 

Description. Carapace elongate, subrectangular in lateral outline with dorsal 
and ventral margins straight, tapering towards the posterior. Anterior margin 



FROM WEST PAKISTAN 83 

broadly and evenly rounded, posterior slightly sub-triangular in right valve but 
almost rounded in the left, posterodorsal margin very slightly concave. Anterior 
and posterior cardinal angles well-developed. Sexual dimorphism rather strong ; 
the presumed males are longer, less high and less wide than the females. Valves 
almost equal. In dorsal view greatest width lies at the anterior third (in the region 
of the subcentral-tubercle). Eye-tubercle rounded, polished and prominent (standing 
out from the carapace). Subcentral-tubercle distinct. Surface ornamentation consists 
of combination of reticulations and small spines. The posterodorsal process is 
divided into two spines (although in some specimens this division is not detectable). 
In a few specimens a posteromedian process is also developed. The anterior and 
posterior margins are decorated with a double row of spines ; the second row lies on 
high anterior and posterior marginal rims. The posterior marginal spines are 
larger and less in number. Duplicature fairly wide. Selvage prominent and sub- 
marginal. Radial pore canals not clearly displayed because of mineralization, but 
appear to be simple, more or less straight with median swellings, 30-35 anteriorly. 
Hinge holamphidont : 

Element Left valve Right valve 

Anterior Socket. Stirpate tooth. 

Anteromedian Subcorneal tooth. Deep socket. 

Posteromedian Locellate shallow groove. Denticulate bar. 

Posterior Deep socket. Tooth, almost rounded in 

lateral view. 

Dimensions (mm). 

L H w 

Io. 4361 Carapace male (holotype) 0-62 0-30 0-22 

Io. 3162 Carapace female 0-52 0-29 0-21 

Io. 3164 Right valve male o-6i 0-29 — 

Io. 3163 Right valve female 0-50 0-28 — 

Comparison. The present species shows some affinity to Trachyleberis (Acantho- 
cythereis) decoris sp. nov. but is shorter, less high and less wide. These two species 
also differ in surface ornamentation. T. (A.) postcornis has a combination of 
reticulations and small spines, while T. (A.) decoris is reticulate with superimposed 
pustules. Further, T. (A.) postcornis has a well-developed posterodorsal process 
divided into two spines and a distinct subcentral-tubercle. This species may also be 
distinguished from T. (A.) procapsus sp. nov. in being smaller and lacking a smooth 
walled area behind the anterior marginal rim. These two species also differ in dorsal 
outline. 

Trachyleberis (Acanthocythereis) decoris sp. nov. 

(Plate 42, figs. 3-6, 8, 9) 

Derivation of name. Latin decoris, beautiful, adorned ; with reference to the 
bejewelled appearance of the pustules and reticulae. 

Diagnosis. Acanthocythereis in which surface ornamentation consists of reticula- 



84 EARLY TERTIARY OSTRACODA 

tions with superimposed pustules. Carapace subrect angular with dorsal and ventral 
margins almost straight and subparallel. 

Holotype. Io. 4359, a male carapace (PI. 42, figs. 3, 4, 5). 

Paratype. Io. 4310. 

Material. Over 250 specimens from the type locality from 18 horizons (sample 
nos. 3604, 3607, 3610, 3613 to 3615, 3629, 3640, 3642, 3645, 3648 to 3650, 3661 to 
3664). 7 specimens from the Zao River section from 3 horizons (sample nos. 24154, 
24173 and 24193). GSPBM 2601-2. 

Type section. Rakhi Nala section. 

Type horizon. Upper Chocolate Clays, sample no. 3640. 

Description. Sexual dimorphism rather marked ; the males are longer in pro- 
portion than the females. Carapace subrect angular in lateral view with dorsal and 
ventral margins almost straight and subparallel. Anterior margin broadly and evenly 
rounded, posterior slightly subtriangular. Both anterior and posterior margins 
ornamented by a double row of short spines, the posterior ones being larger. Anterior 
cardinal angle rounded, posterior cardinal angle well-marked. Greatest height at the 
anterior cardinal angle and greatest length in the middle. In dorsal view greatest 
width lies in the anterior third. Valves almost equal. Surface reticulate with super- 
imposed pustules. Eye-tubercle rounded and distinct. Subcentral-tubercle more or 
less distinct (better seen in slightly worn specimens). A large number of specimens 
(particularly the females) show development of postero ventral prominence. In a few 
specimens a small posterodorsal process also develops, but these characters here are 
regarded as variations within the species. Dupiicature fairly wide with a submarginal 
selvage. Radial pore canals not seen. Muscle scar pattern consists of four adductors 
in a vertical superposition at the posterior margin of the muscle scar pit with a 
U-shaped frontal scar opening towards the anterodorsal corner. Hinge holamphidont : 

Element Left valve Right valve 

Anterior Socket. Slightly stirpate tooth. 

Anteromedian Subcorneal tooth. Denticulate ridge. 

Posterior Deep socket. Somewhat rounded tooth 

in lateral view. 

Dimensions (mm). 

L H w 

I°- 4359 Carapace male (holotype) 0-67 0-32 0-24 

Io. 4310 Carapace female 0-59 0-32 0-23 

Comparison. In some respects this species resembles Trachyleberis (Acantho- 
cythereis) procapsus sp. nov., but differs in lacking the smooth walled area enclosed 
by the anterior marginal rim and compressed anterior and posterior marginal 
platforms. These two species also differ in size, T. (A.) decor is being smaller, higher 
and wider in proportion than T. (A.) procapsus. 

Remarks. This species commonly occurs in the Upper Chocolate Clays of the 
Rakhi Nala section but it is very rare in the Zao River section. 



FROM WEST PAKISTAN 85 

V. OSTRACODA AND EARLY TERTIARY CORRELATION 
IN THE SULAIMAN RANGE 

(a) BlOSTRATIGRAPHIC UNITS 

Throughout the succession the ostracods have revealed a fairly shallow-water 
marine environment. Although Eames (1952a) has recorded small freshwater 
gastropods in the lower part of the Lower Chocolate Clays (in his local zones 8 & 9) of 
the Rakhi Nala section, he believes they were carried down from a closely neigh- 
bouring source and deposited under estuarine conditions. No freshwater ostracods 
have been found, however, and the presence of Neocyprideis sp. in the Shales with 
Alabaster could represent either estuarine or super saline conditions. 

Except for a few gaps, ostracods occur throughout almost the whole succession. 
At many horizons, particularly in the Eocene, samples are completely crowded with 
ostracods. The diversity of the fauna being suggestive of ideal conditions. They 
usually occur in association with larger and smaller benthonic Foraminifera, but 
are very rare or almost absent in samples with rich pelagic Foraminifera. The most 
conspicuous gap in the Eocene succession of the Rakhi Nala and Zao River sections 
which has not yielded any ostracods is the Platy Limestone and the lower part of the 
Lower Chocolate Clays. In the Zao River section the top 600 ft. of the Upper 
Chocolate Clays are devoid of any recognizable ostracods, although at a few horizons 
some Nummulites have been found. 

Rakhi Nala Section 

The following ostracod biostratigraphic units in the Rakhi Nala section have been 
recognized (see Table 4). Each unit is identified by a distinct ostracod fauna, a 
change of faunal suite marking the base. 

Ostracod Biostratigraphic Unit I , Palaeocene (lower part) 

The first Tertiary ostracod assemblage is encountered in the lower part of the 
Gorge Beds (samples from the Venericardia Shales were not available for study). 
Seven out of the eight species recorded are restricted to the unit. The species which 
ranges up into Unit II is Trachyleberis (Acanthocythereis) usitata sp. nov. Alocopo- 
cythere rupina sp. nov., Neocyprideis ? sp.A and Bairdia sp.A are abundant and make 
up over 80% of the ostracod fauna. 

Ostracod Biostratigraphic Unit II, Palaeocene (upper part) 

This Unit contains the Lower Rakhi Gaj Shales. Ostracods are very rare and 
have only been found in the upper part which is very rich in pelagic Foraminifera. 
The ostracods, although very rare, are easily distinguishable from the assemblages 
below and above. Of the eight species found, all are restricted to the present Unit, 
with the exception of Trachyleberis (Acanthocythereis) usitata sp. nov. which is also 
present in the underlying Unit. 

Ostracod Biostratigraphic Unit III, Lower Eocene (lower part) 

This includes the Upper Rakhi Gaj Shales, Green and Nodular Shales and Rubbly 
Limestones. Eames' local zones 3, 4, 5 and 6 he in this Unit. 



86 EARLY TERTIARY OSTRACODA 

This is the first Eocene ostracod assemblage. It is fairly rich and at several 
horizons the ostracods are very abundant. None of the Palaeocene species survive 
and a completely new fauna evolves. The ostracod fauna is of changing suite ; 
species appear and disappear in the unit, but there seems to be no major break of 
any kind in the fauna. Trachyleberis (Trachyleberis) lobuculus sp. nov., Gyrocythere 
parvicarinata sp. nov., Occultocythereis peristicta sp. nov. (with five morphotypes), 
Schizocythere sp.A and Pontocythere sp.A are the most important members restricted 
to the unit. Approximately 50% of the species range up into the overlying Unit IV. 

Ostracod Biostratigraphic Unit IV, Lower Eocene {upper part) 

This consists of the Shales with Alabaster and includes Eames' local zone 7. It has 
a very rich ostracod faunal assemblage. Most of the samples studied were extremely 
rich in ostracods, which are mostly complete carapaces. The most typical species 
confined to the unit are Stigmatocyihere obliqua sp. nov., Phalcocythere dissenta sp. nov. 
Genus C sp. 1 and Genus C sp. 2. More than 50% of the species are restricted to the 
unit, although approximately 44% are common to Unit III, and only one species 
ranges up into Unit V. 

Ostracod Biostratigraphic Unit V , Middle— U pper Eocene 

This comprises the Platy Limestone, Lower Chocolate Clays, Upper Chocolate 
Clays and Pellatispira Beds. Eames' local zones 8 to 15 and Latif's top six pelagic 
foraminiferal zones occur in this unit. The lowest 730 ft., which form the Platy 
Limestone and most of the Lower Chocolate Clays, excluding the top 30 ft., are 
devoid of any recognizable ostracods and are provisionally included in the unit. 
There are 200 ft. of covered sediments in the Lower Chocolate Clays below sample 

3494- 

The Unit is very rich in very well-preserved ostracods. It differs markedly from 
the underlying Unit. All the species except Alocopocythere transcendens sp. nov., 
which survives from the Unit below, appear for the first time, although a few have their 
ancestors in the Unit IV. The first appearance of ostracods in the Unit is in the 
uppermost part of the Lower Chocolate Clays (sample nos. 3498 and 3499), which lies 
at the base of the Globigerina yeguaensis zone of Latif. The ostracod fauna is varied 
and of changing suite. 12% of the species are restricted to the Lower Chocolate 
Clays (topmost portion) ; 25% are confined to the Upper Chocolate Clays (lower 
part) ; and only 8% have been recorded from the Pellatispira Beds. 33% of the 
species are shared between the Lower Chocolate Clays (topmost portion) and Upper 
Chocolate Clays (lower part) ; 17% range from the Lower Chocolate Clays (upper- 
most part) to the Upper Chocolate Clays (upper part) ; 37% are shared between the 
Upper Chocolate Clays (lower part) and Upper Chocolate Clays (upper part) ; 8% 
range from the Upper Chocolate Clays (lower part) to the Pellatispira Beds ; and 12% 
are found in both the Upper Chocolate Clays (upper part) and Pellatispira Beds. 
(The percentages are approximate and are based on the entire ostracod fauna of the 
Unit). 

The genus Alocopocythere nov. occurs abundantly almost throughout the Unit. 



FROM WEST PAKISTAN 87 

Alocopocythere transcendens sp. nov., which ranges up from the underlying Units III 
and IV, is replaced by A. transversa sp. nov. just above the middle of the lower part 
of the Upper Chocolate Clays. This last species has several morphotypes ; in the 
upper part of the Upper Chocolate Clays the papillose form becomes more common 
and in the Pellatispira Beds this is the only morphotype present. Stigmatocy there 
obliqua sp. nov., which was very abundant in the underlying biostratigraphic Unit 
IV, is replaced by the larger Stigmatocythere portentum sp. nov., which has only been 
found in the uppermost part of the Lower Chocolate Clays. Higher up in the 
succession, i.e. in the lower part of the Upper Chocolate Clays the place of S. porten- 
tum is taken by Stigmatocythere lumaria sp. nov. which ranges up into the Pellatispira 
Beds. The genera Cytherella, Cytherelloidea, Krithe, and Paijenborchella are repre- 
sented by several species. The genus Gyrocythere nov. has two species in the Unit. 
Gyrocythere perfecta sp. nov. occurs in the uppermost part of the Lower Chocolate 
Clays but in the lower part of the Upper Chocolate Clays it is replaced by the larger 
Gyrocythere exaggerata sp. nov. The subgenera Scelidocythereis nov. and Paracosta 
nov. are represented by two and three species respectively. Paracosta is known so far 
only from this Unit. The following are some of the most important species of the 
Unit : Bairdoppilata sp.A, Cytherelloidea cf. C. costatruncata Lubimova and Mohan, 
Cytheromorpha sp.A, Cytheropteron sp.D, Alocopocythere transversa sp. nov. (with six 
morphotypes), Patagonacy there ? nidulus sp. nov., Stigmatocythere lumaria sp. nov. 
(with two morphotypes) and Trachyleberis (Acanthocythereis) decoris sp. nov. 



Zao River Section 

The two biostratigraphic Units IV and V of the Rakhi Nala section are found in 
the Zao River section (see Table 5). 

Ostracod Biostratigraphic Unit IV, Lower Eocene (upper part) 

This is very similar to biostratigraphic Unit IV of the Rakhi Nala section. The 
base of the Unit has been taken arbitrarily at the base of the four foot limestone, 
which lies 332 ft. below the base of the Platy Limestone. The actual base of the Unit, 
or the Shales with Alabaster, probably lies much lower in the succession, but sediments 
below the 4 ft. limestone have not been analysed. These have been recorded as the 
undifferentiated Ghazij by the collectors. No megafossils have so far been recorded 
from these sediments and it is unlikely that these would yield any smaller foramini- 
fera or ostracods because of their lithology — mostly silty shales. 

Ostracods have been found in the upper part of the Unit at two horizons (samples 
24107 and 241 10). They are extremely abundant in 24107. Approximately half 
of the Rakhi Nala species of the Unit are found in the Zao River section. None of 
the species range up into Unit V. Stigmatocythere obliqua sp. nov. is the most 
dominant species and makes about one-third of the ostracod fauna. Neocyprideis ? 
sp.B, Neocyprideis sp.C, Pontocyprella sp.B, Pontocyprella sp.C, Xestoleberis sp.C, 
Xestoleberis sp.D, Xestoleberis sp.E, Genus C sp.i and Genus C. sp.2 are some other 
important species. 



88 EARLY TERTIARY OSTRACODA 

Ostracod Biostratigraphic Unit V , Middle-Upper Eocene 

The biostratigraphic Unit V of the Rakhi Nala section occurs in the Zao River and 
is 3743 ^. thick. The Unit includes the Platy Limestone, Lower Chocolate Clays 
and both lower and upper parts of the Upper Chocolate Clays. The Pellatispira 
Beds have not been recorded in the Zao River section. The bottom 460 ft. of the 
Unit comprising the Platy Limestone and the lower part of the Lower Chococlate 
Clays and the top 600 ft. of the upper part of the Upper Chocolate Clays have not 
yielded any ostracods and are only provisionally included in the Unit. 

The Unit is very rich in well-preserved ostracods. The ostracod fauna is com- 
pletely new since none of the species from the Unit below survive. There are 7% 
of the species which are restricted to the upper part of the Lower Chocolate Clays ; 
26% have only been found in the lower part of the Upper Chocolate Clays ; and 17% 
have been recorded from the upper part of the Upper Chocolate Clays only. 24% of 
the species occur in the upper part of the Lower Chocolate Clays and the lower part 
of the Upper Chocolate Clays ; 13% range from the upper part of the Lower Choco- 
late Clays to the upper part of the Upper Chocolate Clays and 41% are shared be- 
tween the lower and upper parts of the Upper Chocolate Clays. 

The ostracod fauna of the Unit in the Zao River section is very similar to that of 
the Rakhi Nala section. It has about 74% of its species in common with the Rakhi 
Nala. These are shown in Appendix 2. As in the Rakhi Nala, Alocopocythere is 
one of the commonest genera and it occurs in great abundance at several horizons. 
It is represented by three related species ; A. transcendens sp. no v., A. transversa 
sp. nov. (with six morphotypes), and A. radiata sp. nov. Stigamatocythere is another 
common genus and has three species in the Unit : S. calia sp. nov., 5. delineata 
sp. nov. and 5. lumaria sp. nov. (with two morphotypes). Among these, 5. lumaria 
is the commonest, occurring in the lower and upper parts of the Upper Chocolate 
Clays. S. calia and S. delineata have so far not been found in the Rakhi Nala section. 
Bairdoppilata sp.A, Pterygocythereis (Pterygocythere) sp.A are more common in the Zao 
River section. Trachyleberis (Acanthocythereis) decoris sp. nov. and Cytheromorpha 
sp.A, which were very common in the Rakhi Nala are rare in the Zao River. The 
subgenus Paracosta nov. which is represented by three species in the Rakhi Nala has 
not so far been recorded from the Zoa River. Phalcocythere spinosa sp. nov. and 
Quadracythere (Hornibrookella) subquadra sp. nov. have only been found in sample 
24161 of the Zao River section, where they occur in association with the larger 
foraminifera Pellatispira orbitoidea. Some of the more important members of the 
unit are : Alocopocythere transcendens sp. nov., Alocopocythere transversa sp. nov., 
Bairdoppilata sp.A, Cytherelloidea cf. C. costatruncata Lubimova and Mohan, 
Patagonacy there ? nidulus, sp. nov. and Stimatocy there lumaria sp. nov. 



Shpalai Khwara Section 

The ostracod biostratigraphic Unit IV of the Rakhi Nala and Zao River sections 
is also represented in the Shpalai Khwara section. 






FROM WEST PAKISTAN 89 

Ostracod Biostratigraphic Unit IV, Lower Eocene {upper part) 

Like the Zao River section, the base of the Unit is taken arbitrarily at the base of 
the 4 ft. limestone, which is 320 ft. below the base of the Platy Limestone. The 
Platy Limestone is only 40 ft. thick in this section. The 12,450 ft. thick sediments 
below the 4 ft. limestone are barren except for a few horizons which contain poorly 
preserved pelagic Foraminifera. These probably represent the following lithological 
units in ascending order : Upper Rakhi Gaj Shales, Green and Nodular Shales, 
Rubbly Limestones and lower part of the Shales with Alabaster. 

Only the upper part of the Unit has yielded ostracods and the fauna is similar to 
that of the Zao River and Rakhi Nala sections. About 70% of its species are in 
common with the Zao River section. Over 40% of the species of the Unit in the 
Rakhi Nala have been recorded from the Shpalai Khwara section. Stigmatocythere 
obliqua sp. nov. is very abundant, particularly in sample 24686, which is absolutely 
crowded with this species. Some other common species are : Neocyprideis ? sp. B, 
Pontocyprella sp.B, Cytherella sp.B, Cytherella sp. and Genus C sp.2. 



(b) Statistical Correlation of ranges of Ostracod Species Common to the 
Rakhi Nala and Zao River Sections. 

The tops and bases of ostracod species common to the Rakhi Nala and Zao River 
sections have been plotted on a graph (Fig. 6). These fall into two rectilinear 
patterns, one in biostratigraphic Unit IV and the other in biostratigraphic Unit V. 

The tops and bases of ostracod species in biostratigraphic Unit IV (i.e in the 
Shales with Alabaster) lie almost in a straight line on the graph ; this, however, is 
because ostracods have only been found at two horizons in the Zao River section. 
The Equations of Correlation for the array of biostratigraphic Unit V (i.e. above the 
Platy Limestone) can be computed from the data given in Appendix 2. This 
method has been discussed in detail by A. B. Shaw in his book 'Time in Stratigraphy', 
published in 1964. The points marked ' + ' in Appendix 2 have been omitted because 
they fall outside the main array. Eighty-one points have been considered. The 
Equations of Correlation between the Rakhi Nala and Zao River sections can be 
calculated as follows : 

RN = RN + £ ( RN ~ RN ) (ZR— ZR) (2R—ZR), where RN = Rakhi Nala and 



S(ZR— ZR)' 

6638+ ^5228 (ZR-2253) 
^ 48,697965 v ™ 



ZR = Zao River. 



= 0-4451 ZR + 5035 • 2 (1) 

and 

ZR = ZR + S(RN~RN) (ZR-ZR) ^ 

E(RN— RN) 2 



go EARLY TERTIARY OSTRACODA 

« 2253 + 21 > 6 ^ 228 (RN-6638) 
11,153941 V 3 ' 

== 1-9433 RN— 10646 • 5 (2) 

Any point in the Zao River section in biostratigraphic Unit V can be correlated 
with the corresponding point in the Rakhi Nala section by means of Equation (1). 
Similarly any point in the Rakhi Nala section can be correlated with the correspond- 
ing point in the Zao River section by using Equation (2). 

The Coefficient of Correlation is expressed by the formula : 



r = y/bi x b 2 

By substituting the values b x and b 2 , we get 



r = Vo-445 1 x 1*9433 

= V * 86 49 
= 0-930 

This high value of r is above the 99% confidence level. 
The standard error of estimate for RN (S R ^) 



S(RN— RN) : 

N 



where RN — RN is the difference between each observed point and its computed 
equivalent and N is the number of entries. 



Hence, S R A N —''"'""' 



- ^18324-554 
= 135-4 ft- 



The standard error of estimate for ZR (S/r) 



'(ZR— ZR) : 



N 



6464244-61 



81 

= n/79805-489 
= 282-5 ft. 

When the two straight lines given by Equations (1) and (2) are drawn on a graph, 
they intersect one another at an angle of 3 . Since the Rakhi Nala section has been 
regarded as the standard section, therefore, for practical purposes only one straight 



91 



iph. This is the 
iver with parallel 



divided into five 
these Units, I and 
Dcene. Biostrati- 
Zao River section 
:tions have almost 
ikhi Nala is also 

n the Rakhi Nala 
pecies common to 
tion can easily be 
vice versa, (see 
s also been calcu- 
in the Zao River 
rrelated with any 

hi Nala and Zinda 
Hiver and Shpalai 
es with Alabaster 
/s (upper Eocene), 
e Shpalai Khwara 

poorly preserved 
bly equivalent to 
ly Limestones and 
i sediments below 
and are probably 

in the northern 
ible for abundant 

tide with Eames' 
shales, Green and 
)d fauna and are 
i is in the Kirthar 
y. This occurs in 
n the White Marl 
i Lower Chocolate 
White Marl Band 

section has been 
nes and Nagappa. 



i ! 



Graphic representation of ranges "' "°»™™h species common to 

the Rakhi Nala and Zao River sec '™ g Regression and standard 

error of Rakhi Nala on Zao River indicate d by lines. 



INDEX 

+ Top of range 

• Base of range 

4 Coincident base and top 
(3 Point not used 
G-&N.S. Green and nodular shales 
R.Lst. Rubbly limestones 
S. w.A. Shales with alabaster 
P. L Platy limestone 

L.CC Lower chocolate clays 
U.C.C. Upper chocolate clays 
WMB. White marl band 
p b. Pellatispiro beds 

Data from Appendix 2. 



V £ 



13 53 iS tsff.5,52 4A + 36 



21 5i:i\' — d~" W&- 




U5\ZR .5635-2 



Feet above the base of the Venericardia Shales. 




HMk-U C.C.lo*e> 
iBl 



6500 

* PART- 



7000 

"U.C.C. UPPER PART 



MIDDLE EOCENE - 



RAKHI NALA 
FIG. 7 



►j*-UPPER EOCENE- 



qi 



FROM WEST PAKISTAN 91 

line (i.e. RN = o*445iZR + 5635*2) has been drawn on the graph. This is the 
Correlation or Regression Line of the Rakhi Nala on the Zao River with parallel 
dotted lines showing the standard error of estimate. 

(c) Conclusions 

The Palaeocene and Eocene of the Rakhi Nala section can be divided into five 
distinct biostratigraphic units on the basis of Ostracoda. Two of these Units, I and 
II, occur in the Palaeocene and three, III, IV and V, in the Eocene. Biostrati- 
graphic Unit IV of the Rakhi Nala section is represented in the Zao River section 
by at least 332 ft., and Unit V by 3743 ft. The Units in the two sections have almost 
identical ostracod faunas. Biostratigraphic Unit IV of the Rakhi Nala is also 
represented in the Shpalai Khwara section by at least 320 ft. 

The Equations of Correlation of biostratigraphic Unit V between the Rakhi Nala 
and Zao River sections have been calculated by means of ostracod species common to 
the two sections. From these two equations any point in one section can easily be 
correlated with the corresponding point in the other section or vice versa, (see 
Fig. 6). The standard error of estimate for the two equations has also been calcu- 
lated. Since only the upper part of biostratigraphic Unit IV in the Zao River 
section has yielded ostracods, only this part of the unit can be correlated with any 
certainty. 

Eames' lithological units for the southern Sulaiman Range (Rakhi Nala and Zinda 
Pir) extend into the northern part of the Sulaiman Range (Zao River and Shpalai 
Khwara). This is particularly true for sediments from the Shales with Alabaster 
(upper Lower Eocene) to the upper part of the Upper Chocolate Clays (upper Eocene) . 
Sediments below the upper part of the Shales with Alabaster of the Shpalai Khwara 
section are unfossiliferous except for a few horizons containing poorly preserved 
pelagic foraminifera. These are 12,450 ft. thick and are probably equivalent to 
Eames' Upper Rakhi Gaj Shales, Green and Nodular Shales, Rubbly Limestones and 
lower part of the Shales with Alabaster. In the Zao River section sediments below 
the upper part of the Shales with Alabaster are undifferentiated and are probably 
unfossiliferous. This suggests that environmental conditions in the northern 
Sulaiman Range during most of the Early Eocene were not suitable for abundant 
marine life. 

The faunal breaks in the sections studied do not always coincide with Eames' 
lithological subdivisions. For example, the Upper Rakhi Gaj Shales, Green and 
Nodular Shales and Rubbly Limestones have a similar ostracod fauna and are 
regarded as one ostracod biostratigraphic unit. Another example is in the Kirthar 
Formation where a new fauna appears before a change in lithology. This occurs in 
the uppermost part of the Lower Chocolate Clays (i.e. just below the White Marl 
Band). Most of the species range from the uppermost part of the Lower Chocolate 
Clays to the lower part of the Upper Chocolate Clays, although the White Marl Band 
lies in between. 

The Palaeocene/Lower Eocene boundary in the Rakhi Nala section has been 
drawn at the base of the Nummulites irregularis Limestone of Eames and Nagappa. 



92 EARLY TERTIARY OSTRACODA 

(Bayliss, however, identified this as Nummulites crasseornata (Henrici) form B.) 
This is in agreement with Eames, Bayliss and Latif . The ostracod faunal assemblages 
below and above the irregularis Limestone are completely different and have no 
species in common. These assemblages have been included in ostracod biostrati- 
graphic Units II and III respectively. The Palaeocene and Lower Eocene boundary 
in fact has been placed between these two biostratigraphic units. The ranges of 
ostracod species found in the two biostratigraphic units are shown in Appendix 2. 

The Shales below the irregularis Limestone have a very rich assemblage of pelagic 
Foraminifera and have been assigned to the Globrotalia rex Zone by Latif. Dr. 
Banner, lately of the British Petroleum Co. Ltd., who very kindly examined these 
samples, considers them to be of the high Globorotalia rex Zone with derived Lower/ 
Middle Palaeocene pelagic Foraminifera. 

The Lower/Middle Eocene boundary in the Rakhi Nala, Zao River and Shpalai 
Khwara sections has been placed at the base of the Platy Limestone. This is in 
conformity with Eames, who examined the Rakhi Nala and Zinda Pir sections of the 
Sulaiman Range. Bayliss and Latif, who worked on the Rakhi Nala section, how- 
ever, have drawn the boundary in the uppermost part of the Lower Chocolate Clays 
(i.e. below sample 3498). The Platy Limestone serves as an important horizon 
marker in the region. The Lower/Middle Eocene boundary lies between ostracod 
biostratigraphic Units IV and V, which have very different ostracod assemblages. 
Except for Alocopocythere transcendens sp. nov., none of the Lower Eocene ostracod 
species survive into the Middle Eocene. 

The Middle/Upper Eocene boundary in the Rakhi Nala and Zao River sections has 
been placed between the lower and upper parts of the Upper Chocolate Clays. The 
upper part of the Upper Chocolate Clays contains the genus Pellatispira, which is of 
Upper Eocene age. In the Rakhi Nala section the boundary is taken arbitrarily 
between samples 3627 and 3628. This is approximately the same level as drawn by 
Eames (1952), who recorded the first appearance of Pellatispira just above this 
horizon in the section. Bayliss, however, recorded Pellatispira only from one 
horizon (sample 3657) in the Pellatispira Beds. Latif has placed the boundary in the 
middle of his Chiloguembelina aff. martini Zone (i.e. above sample 3618). In the 
Zao River section sample 24161 contains specimens of Pellatispira in abundance. 
These have been assigned to Pellatispira orbitoidea (Povale) sensu Rao 1941 by Dr. 
C. G. Adams of the British Museum (personal communication), who very kindly 
examined these specimens. According to Dr. Adams these fall midway between 
P. orbitoidea and P. madaraszi var. indica. The Middle/Upper Eocene boundary in 
the Zao River section can, therefore, safely be placed below sample 24161. 

The Middle and Upper Eocene ostracod fauna of the Rakhi Nala and Zao River 
sections is of changing suite and has been included in ostracod biostratigraphic 
Unit V. It does not show any sharp break between the Middle and the Upper 
Eocene. Some species are restricted to the Middle Eocene, but others range from 
the Middle to the Upper Eocene. Some of the important species restricted to the 
Middle Eocene are : Actinocythereis ? quasibathonica sp. nov., " Anommatocythere " 
confirmata sp. nov., Echinocythereis (Scelidocythereis) rasilis sp. nov., Cytheropteron 
sp.C, Gyrocythere exaggerata sp. nov., Trachyleberis (Trachyleberis) bimammillata 



FROM WEST PAKISTAN 



93 



sp. nov. Some of the common species which range from the Middle to the Upper 
Eocene are : Alocopocythere transversa sp. nov., Bairdoppilata sp.A, Cytherelloidea 
cf. C. costatruncata Lubimova and Mohan, Cytheromorpha sp.A, Cytheropteron sp.D, 
Paijenborchella sp.C, Patagonacy there ? nidulus sp. nov., Pterygocythereis (Pterygocy- 
there) sp.A and Stigmatocythere lumaria sp. nov. (A complete list of these species is 
given in Tables 4 & 5). 

vi. appendices 
Appendix i 

Sor Range Lease 58, measured section at locality 460. 
Section measured by J. A. Reinemund. 



Thickness (feet) Description of Unit 

10+ Claystone, grey 

42 Conglomerate containing limestone and chert 

pebbles, cobbles, boulders as much as 8 in. 
across ; matrix of medium grained, yellowish 
brown sandstone forms about 20% of rock. 
42 Concealed by talus 

18 Claystone, medium grey, not fissile, semiplastic, 

containing scattered fossils. Calcareous nodules 
at top ; silty and carbonaceous in lower part. 
2-3 Sandstone, very fine grained to silty brownish- 
grey, imperfect and irregular bedding, contains 
carbonized plant fragments and vertical root 
moulds. 
24 Claystone, dark olive grey, not fissile, silty in 

upper few feet and lower few feet ; contains 
irregular coal layers as much as 4 in. thick in 
lower 2 ft. 
7^ Sandstone, fine to very fine grained, light brown- 
ish grey, mostly even beds 2-8 in. thick, locally 
cross-bedded. 
2 Siltstone, poorly bedded, carbonaceous, contain- 

ing very carbonaceous layers as much as \ in. 
thick in top 2 in. 
i\ Claystone, silty, olive grey, not fissile, containing 

carbonised plant chips. 
5 Siltstone, brownish grey, imperfect beds, cross 

laminated. 
45 Claystone, silty at top, olive grey not fissile. 



Sample No. 



460a (near top) 



460b (6-8 above 

bottom) 
460c (3-4 feet 

above bottom) 
46od 



46oe (5-6 feet 
above bottom) 

46of (1-2 feet 
above bottom) 



94 



EARLY TERTIARY OSTRACODA 



Thickness (feet) Description of Unit 

8 Claystone, containing profuse white calcareous 

concretions. 
2 Claystone, olive grey, fissile, grading down into 

siltstone, yellowish-brown, hard, fossiliferous. 
50+ Claystone, slightly fissile, olive grey. 



Sample No. 



46og (Channel 

sample) 
460I1-0 



Appendix 2 

List of ostracod species common to the Rakhi 
Nala and Zao River Sections 



No. Species 

5 " Anommatocy there " laqueta sp. no v. 

13 Phalcocythere dissenta sp. no v. 

14 Stigmatocy there obliqua sp. nov. 
21 Cytherella sp.C 

35 Neocyprideis ? sp.G 

36 Neocyprideis sp.C 

44 Xestoleberis sp.C 

45 Xestoleberis sp.D 

46 Xestoleberis sp.E 

48 Genus Csp.i 

49 Genus Csp.2 

50 Bairdia sp.C 

51 Bairdia sp.D 

5 2 Cytherella sp . B 

53 Pontocyprella sp.B 

54 Pontocyprella sp.C 

1 Actinocythereis ? quasibathonica sp. nov. 

2 Alocopocythere transcendens sp. nov. 
3a yl . transversa sp. nov. Morphotype A 
3b A . transversa sp. nov. Morphotype B 
3c A . transversa sp. nov. Morphotype C 
3d A . transversa sp. nov. Morphotype D 
3e A . transversa sp. nov. Morphotype E 
31 A . transversa sp. nov. Morphotype F 
4 A . radiata sp. nov. 

6 " Anommatocythere " confirmata sp. nov. 

7 Echinocythereis (Scelidocythereis) rasilis 

sp. nov. 

8 E. (S.) multibullata sp. nov. 

9 Gyrocythere exaggerata sp. nov. 
10 Hermanites palmatus sp. nov. 



Rakhi Nala 
Base Top 

5223 
5195 
5373 
5195 
5373 



4045 
4968 

4815 
5112 

4815 



5373 



4919 
5112 

48i5 
4687 
4687 
3682 + 

3995 
2687+ 

5023 
4687 



5208 

5195 
5208 

5304 
5373 
4815 
5195 
5223 

5304 
5208 



6369 6524 

3215+ 6488 

6575 6706 

6589+ 6690 

6764 7014 

6839 7-37 

6839 7107 

6943 7037 

7029 

6138 6424 



6138 

6531 
6401 
6401 



6463 

6589+ 

6515 
6488 



294 

294 
294 

294 



Zao River 
Base Top 

252 

252 
252 

252 
252 
252 
252 

252 

252 

252 

252 

252 

252 

252 

252 

252 

1872 1994 

650+ 1948 

2032 2190 

3384+ 
2190 3230 
2504 3230 
2086 3186 
2504 2808 

2712 
1570 1948 



1570 
1994 

1570 

994 



1986 

3095 
1948 
2060 



FROM WEST PAKISTAN 95 

No. Species 

11 Hermanites scopus sp. nov. 

12 Patagonacythere ? nidulus sp. nov. 
15a Stigmatocythere lumaria sp. nov. 

Morphotype A 

15b S. lumaria sp. nov. Morphotype B 

16 Trachyleberis (Trachyleberis) bimammillata 

sp. nov. 

17 T. (Acanthocythereis) postcornis sp. nov. 

18 T. (Acanthocythereis) decoris sp. nov. 

19 Aglaiocypris sp.B 

20 Bairdoppilata sp.A 

22 Cytherella sp.E 

23 Cytherella sp.F 

24 Cytherella sp.G 

25 Cytherelloidea cf . C. 

costatruncata Lubimova and Mohan 

26 Cytherelloidea sp.E 

27 Cytherelloidea sp.F 

28 Cytheromorpha sp.A 

29 Cytheropteron sp.C 

30 Cytheropteron sp.D 

31 Krithe sp.C 

32 Krithe sp.D 

33 Krithe sp.E 

34 Krithe sp.F 

37 Neocyprideis ? sp.D 

38 Paijenborchella sp.C 

39 Paijenborchella sp.E 

40 Paijenborchella sp.F 

41 Propontocypris sp.A 

42 Pterygocythereis (Pterygocy there) sp.A 

43 Schizocytheresp.B 
47 Xestoleberis sp.G 

+ Points omitted from computation. 



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Rakhi Nala 


Zao River 


Base 


Top 


Base 


Top 


6138 


6488 


1766 


1872 


6575 


7118 


2032 


3384 


6531 


7121 


2060 


3384 


6839 


7029 


2712 


i 

6369 


6463 


1872 


1948 


6l2I 


6138 


994 


1766 


6200 


7124 


1994 


3384 


641 


5 


2190 


3040+ 


6138 


7014 


794 


3186 


6l2I 


6401 


994 


2032 


6424 


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3040 


6l2I 


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6l2I 


7001 


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6138 


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6I2I + 


7029 


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6l2I 


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631 1 


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2266 


6575 


6985 


2060 


3130 


6138 


6524 


994 


1994 


6138 


6931 


1766 


3130 



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FROM WEST PAKISTAN 97 

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Madras, 604 pp. 
Latham, M. H. 1938. Some Eocene Ostracoda from North-West India. Proc. R. Soc. 

Edinb. 59 (1) : 38-48, text figs. 1-8. 
Latif, M. A. 1 96 1. The use of pelagic Foraminifera in the sub-division of the Palaeocene- 

Eocene of the Rakhi Nala, West Pakistan. Geol. Bull. Panjab Univ., Lahore, 1 : 31-46, 

pis. 1-5. 
1963. Some related groups of pelagic Foraminifera in the Palaeocene-Eocene of the 

Rakhi Nala, West Pakistan. Geol. Bull. Panjab Univ., Lahore, 3 : 19-24, pis. 1-3. 
1964. Variation in abundance and morphology of pelagic Foraminifera in the Palaeocene- 
Eocene of the Rakhi Nala, West Pakistan. Geol. Bull. Panjab Univ., Lahore, 4 : 29-100, 

pis. 1— 11. 
Lubimova, P. S., Guha, D. K. & Mohan, H. i960. Ostracoda of Jurassic and Tertiary 

deposits from Kutch and Rajasthan (Jaisalmer), India. Bull. geol. Min. Met. Soc. India, 

Calcutta, 22 : 1-60, pis. 1-4. 
Moore, R. C. (Editor). 1961. Treatise on Invertebrate Paleontology. Part Q, Arthropoda 3. 

Geological Society of America and University of Kansas Press. 
Moos, B. 1963. Uber einige der " Cythere macropora " Bosquet 1852 (Ostr.) ahnliche Arten 

aus verschiedenen Tertiarstufen. Geol. Jb., Hannover, 82 : 21-42, pis. 1-2. 
1965. Die ostraceoden-Fauna des Unteroligozans von Biinde (Bl. Kerford-West 3817) 

und einige verwandte jungere Arten (Ostr., Crust.). Geol. Jb. Hannover, 82 : 593 — 630, 

pis. 34-39- 
Nagappa, Y. 1959. Foraminiferal biostratigraphy of the Cretaceous-Eocene succession in the 

India-Pakistan-Burma region. Micropaleontology , New York, 5 (2) : 145-192. 
Neviani, A. 1928. Ostracodi fossili dTtalia. 1. Vallebiaja (Calabriano) . Memorie Accad. 

pont. Sci. Roma, 11 : 1-120. 
Nuttall, W. L. F. 1925. The stratigraphy of the Laki Series (Lower Eocene of parts of Sind 

and Baluchistan). Q. J I geol. Soc. Lond., 81 (3) : 417-453. 
1926. The zonal distribution and description of the larger foraminifera of the Middle and 

Lower Kirthar Series (Middle Eocene) of parts of Western India. Rec. geol. Surv. India, 

Calcutta, 59 : 115-164, pis. 1-8. 
Oertli, H. J. 1956. Ostracoden aus der Oligozanen und Miozanen Molasse der Schweiz. 

Diss. Univ. Basel. Separatabdruck Schweiz. palaeontol., Abhandl., 74 : 1-120. 
Pinfold, E. S. 1918. Notes on structure and stratigraphy in the North-West Punjab. 

Rec. geol. Surv. India, Calcutta, 49 (3) : 137-160. 



98 EARLY TERTIARY OSTRACODA 

Pinfold, E. S. 1939. The Dunghan Limestone and the Cretaceous-Eocene unconformity in 

North-West India. Rec. geol. Surv. India, Calcutta, 74 (2) : 189-198. 

1940. Correlation of Laki Beds. Geol. Mag. London, 77 : 1-331. 

Pokorny, V. 1964. The taxonomic delimitation of the subfamilies Trachyleberidinae and 

Hemicytherinae (Ostracoda, Crustacea) Act. Univ. Car olinae geol. Prague, 3 : 255-274. 
1965. Principles of Zoological Micropalaeontology . Earth sci. International Ser. 20 : 

1-465. Translated from the German Edition of 1958. 
Puri, H. S. 1953. The ostracode genus Trachyleberis and its ally Actinocythereis. Am. Midi. 

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Surv. Fla., 36 (Ostracoda) : 217-309. 
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India. Jour. geol. Soc. India, Bangalore, 3 : 63-69, pis. 1-4. 
Reyment, R. A. 1963. Studies on Nigerian Upper Cretaceous and Lower Tertiary Ostracoda 

part 2 : Danian, Paleocene and Eocoene ostracoda. Stockh. Contr. Geol., Stockholm, 10 : 

1-286, 23 pis. 
Ruggieri, G. 1962. Gli ostracodi marini del Tortoniano (Miocene medio superiore) di Enna, 

nella Scilia centrale. Paleontogr. ital. Pisa, 56 (n. ser. vol. 26) : 1-68, 17 pis. 
Shaw, A. B. 1964. Time in Stratigraphy. McGraw-Hill Book Company, New York, London, 

365 PP- 

Simpson, G. G., Roe, A. & Lewontin, R. C. i960. Quantitative Zoology. Harcourt, Brace 

and Co., New York. 
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(in press). 
Sylvester-Bradley, P. C. 194 1. The shell structure of the ostracoda and its application to 

their palaeontological investigation. Ann. Mag. nat. Hist., London, Ser. 11, 8 : 1-33. 

1948. The ostracode genus Cythereis. J. Paleont., Tulsa, 22 (6) : 792-797. 

1951. The Subspecies in Palaeontology. Geol. Mag. London, 88 (2) : 88-102. 

— — 1956. The structure, evolution and nomenclature of the ostracod hinge. Bull. Br. Mus. 

nat. Hist. (Geol.), London, 3 (1) : 1-2 1. 
Sylvester-Bradley, P. C. & Harding, J. P. 1954. Postscript notes of the ostracode 

Trachyleberis. J. Paleont., Tulsa, 28 (5) : 560-562. 
Tewari, B. S. & Tandon, K. K. i960. Kutch Microfauna — Lower Tertiary Ostracoda. 

Proc. natn. Inst. Sci. India Calcutta, 26B, 4 : 147-167, pis. 1-6. 
Triebel, E. 1958. Zwei neue Ostracoden-Gattungen aus dem Lutet des Pariser Beckens. 

Senckenberg. leth., Frankfurt a.M. 39 (1-2) : 105-117, 3 pis. 
196 1. Geschlechts-Dimorphismes und Asymmetric der Klappen bei der Ostracoden- 

gattung Occultocythereis. Senckenberg. leth., Frankfurt a.M. 42 (3-4) : 205-225, 5 pis. 
Van Hinte, J. E. 1962. Ostracoden aus dem Alttertiar des Sonnberges, Karnten, Oesterreich. 

Proc. K. ned. Akad. Wet., Amsterdam, Ser. B 65 (2) : 166-189. 
1964. A new Occultocythereis species of the Austrian Eocene. Proc. K. ned. Akad. Wet., 

Amsterdam, Ser. B 67 (1) : 108-115. 
Van Morkhoven, F. P. C. M. 1962. Post-Palaeozoic Ostracoda. 1, 204 pp. Elsevier Pub- 
lishing Company, Amsterdam. 

1963. Post-Palaeozoic Ostracoda. 2,478 pp. Elsevier Publishing Company, Amsterdam. 

Wadia, D. N. 1953. Geology of India. MacMillan and Co. Ltd. 

Williams, M. D. 1959. Stratigraphy of the Lower Indus Basin, West Pakistan. Fifth world 

Petrol. Cong., New York, section 1, paper 19, pp. 377-394, text-figs. 1-5. 

Qadeer Ahmad Siddiqui, M.Sc, Ph.D., 

Dept. of Geology, 

St. Mary's University, 

Halifax, Nova Scotia, 

Canada. 



PLATE i 

Actinocythereis ? quasibathonica sp. nov. 

Figs, i, io. Dorsal and right views, carapace male, X 70. Paratype, Io. 4260. Upper 
Chocolate Clays (lower part), sample 3613, Rakhi Nala. 

Figs. 2, 3, 11, 12. Dorsal, ventral, left and right views, carapace female, x 70. Holotype, 
Io. 431 1. Upper Chocolate Clays (lower part), sample 361 1, Rakhi Nala. 

Fig. 6. Dorsal view of hinge, left valve male, x 230. Paratype, Io. 3101. Upper Choco- 
late Clays (lower part), sample 3613, Rakhi Nala. 

Figs. 7, 13. 7, dorsal view of hinge x 230 ; 13, anterior radial pore canals X 230. Right 
valve male. Paratype, Io. 3100. Upper Chocolate Clays, sample 361 1, Rakhi Nala. 

Alocopocy there transcendens gen. et sp. nov. 
Figs. 4, 5, 8, 9. Dorsal, ventral, right and left views, carapace male, x 90. Paratype, 
Io. 3104. Upper Chocolate Clays (lower part), sample 3607, Rakhi Nala. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 1 




PLATE 2 

Alocopocy there trans cendens gen. et sp. nov. 

Figs, i, 6. External and dorsal views, left valve female, x 90. Holotype, Io. 4315. Upper 
Chocolate Clays (lower part), sample 24148, Zao River. 

Fig. 2. Muscle scars ( x 200) showing four adductors and an oval frontal scar. Right valve 
male (broken), x 90. Paratype, Io. 3106. Upper Chocolate Clays, sample 24151, Zao River. 

Fig. 3. Anterior radial pore canals x 128. Left valve female. Paratype, Io. 4261. Upper 
Chocolate Clays (lower part), sample 24148, Zao River. 

Figs. 4, 7. External and dorsal views, right valve female, x 90. Paratype, Io. 3105. 
Upper Chocolate Clays (lower part), sample 24148, Zao River. 

Alocopocy there rupina sp. nov. 
Figs. 5, 8-10. Right, left, dorsal and ventral views, carapace male x 90. Holotype, 
Io. 4314. Gorge Beds, sample 31 11, Rakhi Nala. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 2 




PLATE 3 

Alocopocy there rupina sp. nov. 
Figs. 1-4. Left, right, dorsal and ventral views, carapace female, x 90. Paratype, 
Io. 4262. Gorge Beds, sample 31 11, Rakhi Nala. 

Alocopocy there abstracta sp. nov. 

Figs. 5-8. Left, dorsal, ventral and right views, carapace male, x 90. Paratype, Io. 4263. 
Upper Rakhi Gaj Shales, sample 3163, Rakhi Nala. 

Figs. 9-1 1. Right, dorsal and ventral views, carapace female X 90. Holotype, Io. 4312. 
Upper Rakhi Gaj Shales, sample 3163, Rakhi Nala. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. g 



PLATE 3 




PLATE 4 

Alocopocythere abstracta sp. nov. 
Fig. i. Left view, carapace female, x 90. Holotype, Io. 4312. 
sample 3163, Rakhi Nala. 



Upper Rakhi Gaj Shales, 



Alocopocythere coarctata sp. nov. 

Figs. 2-5. Dorsal, ventral, left and right views, carapace male 
Shales with Alabaster, sample 3448, Rakhi Nala. 

Figs. 6-9. Dorsal, ventral, left and right views, carapace female, x 90 
Shales with Alabaster, sample 3458, Rakhi Nala. 



X 90. Paratype, Io. 4264. 
Holotype, Io. 4313. 



Alocopocythere longilinea sp. nov. 
Figs. 10-13. Dorsal, right, ventral and left views, carapace male, x 90. Holotype, Io. 4318 
Shales with Alabaster, sample 3443, Rakhi Nala. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 4 




PLATE 5 

Alocopocythere longilinea sp. nov. 
Figs. 1-3, 6. Left, right, dorsal and ventral views, carapace female, x 90. Paratype, 
Io. 4265. Shales with Alabaster, samples 3443, Rakhi Nala. 

Alocopocythere transversa sp. nov. 
Morphotype A 
Figs. 4, 5, 7, 9. Dorsal, ventral, left and right views, carapace male, X 90. Paratype, 
Io. 4266. Upper Chocolate Clays (lower part), sample 24155, Zao River. 

Figs. 8, 10. Left and right views, carapace female, x 90. Holotype, I0.4316. Upper 
Chocolate Clays (lower part), sample 24155, Zao River. 



Bull. Br. Mas. nat. Hist. (Geol.) Suppl. 9 



PLATE 5 




PLATE 6 

Alocopocy there transversa sp. nov. 
Morphotype A 
Figs, i, 2. Dorsal and ventral views, carapace female, x 90. Holotype, Io. 4316. Upper 
Chocolate Clays (lower part), sample 24155, Zao River. 

Figs. 3,4. Dorsal and internal views, right valve male, x 90. Paratype Io. 3107. Upper 
Chocolate Clays (lower part), sample 3625, Rakhi Nala. 



Morphotype C 
Figs. 5, 7. Left and right views, carapace male, 

Chocolate Clays (upper part), sample 24183, Zao River. 
Figs. 6, 8. Left and right views, carapace female, 

Chocolate Clays (upper part), sample 24183, Zao River. 



X 90. Paratype, Io. 4267. Upper 
X 90. Paratype, Io. 4268. Upper 



Bull. Br. Mus. nal. Hist. (Geol.) Suppl. 9 



PLATE 6 




PLATE 7 

Alocopocy there transversa sp. nov. 
Morphotype C 
Figs, i, 2. Dorsal and ventral views, carapace male, x 90. 
Chocolate Clays (upper part), sample 24183, Zao River. 

Figs. 3, 4. Dorsal and ventral views, carapace female, x 90. 
Chocolate Clays (upper part), sample 24183, Zao River. 



Paratype, Io. 4267. Upper 
Paratype, Io. 4268. Upper 



Morphotype E 
Figs. 5-7. Dorsal, ventral and left views, carapace male, x 90. 

Chocolate Clays (upper part), sample 24175, Zao River. 

Fig. 8. Left view, carapace female, X 90. Paratype, Io. 31 11 

(upper part), sample 24175, Zao River. 



Paratype, Io. 3 no. Upper 
Upper Chocolate Clays 



Bull. By. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 7 




PLATE 8 

Alocopocy there transversa sp. nov. 
Morphotype E 
Fig. i. Right view, carapace male, x 90. Paratype, Io. 31 10. Upper Chocolate Clays 
(Upper part), sample 24175. Zao River. 

Figs. 2, 3, 5. Right, dorsal and ventral views, carapace female, x 90. Paratype, Io. 31 11 
Upper Chocolate Clays (upper part), sample 24175, Zao River. 

Morphotype C 
Fig. 4. Muscle scars ( x 200) showing four adductor, an oval frontal and two mandibular 
scars. Right valve male (broken). Paratype, Io. 4269. Upper Chocolate Clays (upper part), 
sample 24174, Zao River. 

Morphotype F 

Figs. 6, 8. Left and right views, carapace male, x 90. Paratype, Io. 3109. Upper 
Chocolate Clays (upper part), sample 3652, Rakhi Nala. 

Figs. 7, 9. Left and right views, carapace female, x 90. Paratype, Io. 3108. Upper 
Chocolate Clays (upper part), sample 3652, Rakhi Nala. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 8 




PLATE 9 

Alocopocy there transversa sp. nov. 
Morphotype F 
Figs, i, 2. Dorsal and ventral views, carapace male, x 90. Paratype, Io. 3109. Upper 
Chocolate Clays (upper part), sample 3652, Rakhi Nala. 

Figs. 3, 5. Dorsal and ventral views, carapace female, x 90. Paratype, Io. 3108. Upper 
Chocolate Clays (upper part), sample 3652, Rakhi Nala. 

Fig. 4. Internal view to show radial pore canals, right valve female, x 108. Paratype, 
Io. 31 12. Upper Chocolate Clays (upper part), sample 24174, Zao River. 

Alocopocy there radiata sp. nov. 

Figs. 6, 8. Left and right views, carapace male, x 90. Holotype, Io. 4317. Upper 
Chocolate Clays (upper part), sample 3652, Rakhi Nala. 

Figs. 7, 9. Left and right views, carapace female, x 90. Paratype, Io. 4270. Upper 
Chocolate Clays (upper part), sample 3652, Rakhi Nala. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 9 




PLATE 10 

Alocopocy there radiata sp. nov. 

Figs, i, 2. Dorsal and ventral views, carapace male, x 90. Holotype, Io. 4317. Upper 
Chocolate Clays (upper part), sample 3652, Rakhi Nala. 

Figs. 3, 4. Ventral and dorsal views, carapace female, X 90. Paratype, Io. 4270. Upper 
Chocolate Clays (upper part), sample 3652, Rakhi Nala. 

" Anommatocy there " laqueta sp. nov. 

Figs. 5-7. Right, left and dorsal views, carapace male, x 70. Paratype, Io. 4271. Green 
and Nodular Shales, sample 3403, Rakhi Nala. 

Figs. 8-10. Left, right and dorsal views, carapace female, x 70. Holotype, Io. 4320. 
Green and Nodular Shales, sample 3403, Rakhi Nala. 

" Anommatocy there " confirmata sp. nov. 
Figs, ii, 12. Right and left views, carapace male, x 70. Holotype, Io. 4319. Upper 
Chocolate Clays (lower part), sample 3611, Rakhi Nala. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. g 



PLATE 10 




PLATE ii 

" Anommatocythere " confirmata sp. nov. 

Figs, i, 2. Dorsal and ventral views, carapace male, x 70. Holotype, Io. 4319 Upper 
Chocolate Clays (lower part), sample 361 1, Rakhi Nala. 

Fig. 3. Anterior radial pore canals X 232, left valve male. Paratype, Io. 3102. Upper 
Chocolate Clays (lower part), sample 24151, Zao River. 

Figs. 4, 5, 8, 9. Dorsal, ventral, right and left views, carapace female, x 70. Paratype, 
Io. 4272. Upper Chocolate Clays (lower part), sample 24148, Zao River. 

Figs. 6, 7. Anterior and posterior radial pore canals x 232, right valve male. Paratype, 
Io. 3103. Upper Chocolate Clays (lower part), sample 2415 1, Zao River. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 




PLATE 12 

" Anommatocythere " confirmata sp. nov. 

Fig. i. Dorsal view of hinge x 183, left valve male. Paratype, Io. 3102. Upper Chocolate 
Clays (lower part), sample 2415 1, Zao River. 

Fig. 2. Dorsal view of hinge x 183, right valve male. Paratype, Io. 3103. Upper Choco- 
late Clays (lower part), sample 2415 1, Zao River. 

Bradleya ? voraginosa sp. nov. 

Figs. 3, 5, 7, 8. Dorsal left, right and ventral views, carapace male, x 70. Holotype, 
Io. 4321. Upper Chocolate Clays (upper part), sample 24161, Zao River. 

Figs. 4, 6. 9. Dorsal, right and left views, carapace female, x 70. Paratype, Io. 31 15. 
Upper Chocolate Clays (upper part), sample 24161, Zao River. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 12 




PLATE 13 

Buntonia devexa sp. nov. 

Figs, i, 3. Left and right views, carapace male, x 70. Paratype, Io. 31 13. Gorge Beds, 
sample 31 11, Rakhi Nala. 

Figs. 2, 4, 5. Left, dorsal and right views, carapace female, x 70. Holotype, Io. 4322. 
Gorge Beds, sample 31 11, Rakhi Nala. 



Buntonia sp.A 
Figs. 6, 7, 9. Left, right and dorsal views, carapace, x 70. 
Rakhi Gaj Shales, sample 3133, Rakhi Nala. 



Paratype, Io. 31 14. Lower 



Costa (Paracosta) declivis subgen. et sp. nov. 

Figs. 8, 10-12. Left, right, dorsal and ventral views, carapace male, x 68. Holotype, 
Io. 4325. Pellatispira Beds, sample 3662, Rakhi Nala. 

Fig. 13. Right view, carapace female, x 68. Paratype, Io. 4273. Pellatispira Beds, 
sample 3662, Rakhi Nala. 

Fig. 14. Left view, carapace female, x 68. Paratype, Io. 31 16. Pellatispira Beds, sample 
3662, Rakhi Nala. 



Bull. Br. Mm. nat. Hist. (Geol.) Suppl. g 



PLATE 13 




PLATE 14 



Costa (Paracosta) declivis subgen. et sp. nov. 

Fig. 1. Dorsal view, carapace female, x 68. Paratype, Io. 4273. 
sample 3662, Kakhi Nala. 

Fig. 2. Ventral view, carapace female, x 68. Paratype, Io. 31 16. 
sample 3662, Rakhi Nala. 



Pellatispira Beds, 
Pellatispira Beds, 



Costa (Paracosta) compitalis sp. nov. 

Figs. 3, 4, 7, 8. Dorsal, ventral, right and left views, carapace male, 
Io. 4274. Upper Chocolate Clays (lower part), sample 3604, Rakhi Nala. 

Figs. 5, 6, 9, 10. Dorsal, ventral, right and left views, carapace female, 
Io. 4323. Upper Chocolate Clays (lower part), sample 3604, Rakhi Nala. 



X 68. Paratype, 
X 68. Holotype, 



Costa (Paracosta) disintegrata sp. nov. 
Fig. 11. Left view, carapace male, x 68. Paratype, Io. 4275. 
(lower part), sample 3622, Rakhi Nala. 



Upper Chocolate Clays 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 14 




PLATE 15 

Costa (Paracosta) disintegrata sp. nov. 
2, 5, 6. Left, right, dorsal and ventral views, carapace female 
Upper Chocolate Clays (lower part), sample 3621, Rakhi Nala. 
4. Dorsal and ventral views, carapace male, x 68. Paratype, Io 



Figs, i 
Io. 4324. 

Figs. 3 
Chocolate Clays (lower part), sample 3622, Rakhi Nala. 



X 68. Holotype, 
4275. Upper 



Echinocythereis (Echinocythereis) contexta sp. nov. 

Figs. 7, 10. Left and dorsal views, carapace male, x 68. Paratype, Io. 4276. Upper 
Palaeocene, sample 460-j, Sor Range, 8 miles east of Quetta. 

Figs. 8, 13. Left and dorsal views, carapace female, x 68. Holotype, Io. 4326. Upper 
Palaeocene, sample 460-i, Sor Range, 8 miles east of Quetta. 



Echinocythereis (Echinocythereis) elongata sp. nov. 

Figs. 9, 11. Left and right views, carapace male, x 68. Paratype, Io. 3130. Rubbly 
Limestones, sample 3416, Rakhi Nala. 

Figs. 12, 14. Left and right views, carapace female, x 68. Holotype, Io. 4327. Rubbly 
Limestones, sample 3416, Rakhi Nala. 



Bull. Br. Mus. nat. Hist. (Geo].) Suppl. 9 



PLATE 15 




PLATE 16 

Echinocythereis (Echinocythereis) elongata sp. nov. 

Fig. i. Dorsal view, carapace female, x 68. Holotype, Io. 4327. Rubbly Limestones, 
sample 3416, Rakhi Nala. 

Fig. 2. Dorsal view, carapace male, x 68. Paratype, Io. 3130. Rubbly Limestones, 
sample 3416, Rakhi Nala. 

Echinocythereis ( Scelidocyt hereis) multibullata subgen. et sp. nov. 

Figs. 3,5,6. Dorsal, left and right views, carapace male, x 68. Holotype, Io. 4328. Upper 
Chocolate Clays (upper part), sample 241 61, Zao River. 

Figs. 4, 7, 8. Dorsal, right and left views, carapace female, x 68. Paratype, Io. 3134. 
Upper Chocolate Clays (upper part), sample 24 161, Zao River. 

Fig. 9. Internal view to show radial pore canals, right valve female, x 132. Paratype, 
Io. 4277. Upper Chocolate Clays (lower part), sample 24159, Zao River. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 16 




PLATE 17 

Echinocythereis (Scelidocythereis) multibullata sp. now 
Fig. 1. Dorsal view of hinge, left valve female, x 146. Holotype, Io. 4327. Upper 

Chocolate Clays (lower part), sample 24159, Zao River. 

Fig. 2. Dorsal view of hinge, right valve female, x 146. Paratype, Io. 4277. Upper 

Chocolate Clays (lower part), sample 24159, Zao River. 

Fig. 7. Ventral view, carapace male, x 68. Paratype, Io. 3133. Upper Chocolate Clays 

(upper part), sample 24161, Zao River. 

Echinocythereis (Scelidocythereis) sp.A 
Figs. 3, 4, 8, 9. Left, right, dorsal and ventral views, carapace, x 68. Io. 3129. Upper 
Palaeocene, sample 460-i, Sor Range, 8 miles east of Quetta. 

Echinocythereis (Scelidocythereis) rasilis sp. nov. 

Figs. 5, 10. Left and ventral views, carapace male, x 68. Paratype, Io. 4278. Lower 
Chocolate Clays, sample 3499, Rakhi Nala. 

Fig. 6. Left view, carapace female, x 68. Holotype, Io. 4329. Lower Chocolate Clays, 
sample 3499, Rakhi Nala. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. g 



PLATE 17 




PLATE 18 

Echinocythereis (Scelidocythereis) rasilis sp. nov. 

Fig. i. Dorsal view, carapace male, x 68. Paratype, Io. 4278. Lower Chocolate Clays, 
sample 3499, Rakhi Nala. 

Figs. 2, 3. Dorsal and ventral views, carapace female, x 68. Holotype, Io. 4329. Lower 
Chocolate Clays, sample 3499, Rakhi Nala. 

Fig. 5. Right view, carapace male, x 68. Paratype, Io. 3131. Upper Chocolate Clays 
(lower part), sample 24157, Zao River. 

Fig. 7. Right view, carapace female, x 68. Paratype, Io. 3132. Upper Chocolate Clays 
(lower part), sample 24145, Zao River. 

Echinocythereis (Scelidocythereis) sparsa sp. nov. 

Figs. 4, 6. Dorsal and left views, carapace male, x 68. Paratype, Io. 4279. Upper 
Chocolate Clays (lower part), sample 24159, Zao River. 

Figs. 8, 9. Dorsal and left views, carapace female, x 68. Holotype, Io. 4330. Upper 
Chocolate Clays (lower part), sample 24159, Zao River. 

Gyrocythere exaggerata gen. et sp. nov. 

Figs, io, 12. External and internal views, left valve male, x 68. Paratype, Io. 3125. 
Upper Chocolate Clays (lower part), sample 2415 1, Zao River. 

Figs, ii, 14. External and internal views, right valve male, x 68. Paratype, Io. 3127. 
Upper Chocolate Clays (lower part), sample 24151, Zao River. 

Fig. 13. Dorsal view, carapace male (specimen now split giving separate valves Io. 3125 + 
Io. 3127 above). 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. g 



PLATE 1 8 




PLATE 19 

Gyrocythere exaggerata gen. et sp. nov. 

Figs. 1-4. Left, right, dorsal and ventral views, carapace female, x 68. Holotype, Io. 4331. 
Upper Chocolate Clays (lower part), sample 24151, Zao River. 

Fig. 5. Muscle scars x 120 showing four adductors and a U-shaped frontal scar, right valve 
female. Paratype, Io. 4280. Upper Chocolate Clays (lower part), sample 24148, Zao River. 

Fig. 6. Internal view to show radial pore canals, left valve male, x 134. Paratype, Io. 3126. 
Upper Chocolate Clays (lower part), sample 2415 1, Zao River. 

Fig. 7. Internal view to show radial pore canals, right valve female, x 134. Paratype, 
Io. 3124. Upper Chocolate Clays (lower part), sample 24148, Zao River. 

Fig. 8. Dorsal view of hinge x 145, left valve male. Paratype, Io. 3120. Upper Chocolate 
Clays (lower part), sample 2415 1, Zao River. 

Fig. 9. Dorsal view of hinge x 145, right valve male. Paratype, Io. 3122. Upper Choco- 
late Clays (lower part), sample 2415 1, Zao River. 



Bull. By. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 19 




PLATE 20 

Gyrocy there exaggerata gen. et sp. nov. 
Fig. 5. Dorsal view of hinge, right valve female, x 150. Paratype, Io. 3128. 
Chocolate Clays (lower part), sample 24148, Zao River. 



Upper 



Gyrocythere parvicarinata sp. nov. 

Figs, i, 2, 6, 7. Right, left, dorsal and ventral views, carapace male, 
Io. 4334. Green and Nodular Shales, sample 3407, Rakhi Nala. 

Figs. 3, 4, 8, 12. Right, left, dorsal and ventral views, carapace female, 
Io. 4281. Green and Nodular Shales, sample 3407, Rakhi Nala. 



X 68. Holotype, 
X 68. Paratype, 



Gyrocythere grandilaevis sp. nov. 

Figs. 9, 10. Left and right views, carapace male, x 68. Holotype, Io. 4332. Shales with 
Alabaster, sample 3463, Rakhi Nala. 

Figs, ii, 12. Left and right views, carapace female, x 68. Paratype, Io. 4282. Shales 
with Alabaster, sample 3463, Rakhi Nala. 



Bull. Br. Mus. not. Hist. (Geol.) Suppl. 9 



PLATE 










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, 



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, 



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PLATE 21 

Gyrocythere grandilaevis sp. nov. 

Figs, i, 2. Dorsal and ventral views, carapace male, x 68. Holotype, Io. 4332. Shales 
with Alabaster, sample 3463, Rakhi Nala. 

Figs. 3, 4. Dorsal and ventral views, carapace female, x 68. Paratype, Io. 4282. Shales 
with Alabaster, sample 3463, Rakhi Nala. 



Gyrocythere mitigata sp. nov. 

Figs. 5-8. Left, right, dorsal and ventral views, carapace male, x 70. 
Lower Chocolate Clays, sample 241 31, Zao River. 

Figs. 9, 11. Dorsal and external views, left valve female, x 70. 
Lower Chocolate Clays, sample 24131, Zao River. 

Fig. io. Right view, carapace female, x 70. Paratype, Io. 4283. Lower Chocolate Clays, 
sample 34131, Zao River. 



Holotype, Io. 4333. 
Paratype, Io. 31 19. 



Bull. Br. Mits. nat. Hist. (Geol.) Suppl. 9 



PLATE 21 




PLATE 22 

Gyrocythere perfecta sp. nov. 

Figs, i, 2, 5, 9. Left, right, dorsal and ventral views, carapace male, x 68. Paratype, 
Io. 4281. Lower Chocolate Clays, sample 3499, Rakhi Nala. 

Figs. 3, 4, 7, 8. Left, right, dorsal and ventral views, carapace female, x 68. Holotype, 
I°- 4335- Lower Chocolate Clays, sample 3499, Rakhi Nala. 

Fig. 6. Muscle scars x 140, right valve male. Paratype, Io. 3 121. Lower Chocolate Clays, 
sample 3499, Rakhi Nala. 

Fig. 10. Internal view to show radial pore canals, right valve female, x 134. Paratype, 
Io. 3120. Lower Chocolate Clays, sample 3498, Rakhi Nala. 

Hermanites cracens sp. nov. 
Fig. 11. Ventral view, carapace, x 70. Holotype, Io. 4336. Gorge Beds, sample 3111, 
Rakhi Nala. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 22 




Figs. 1-3. 
sample 31 11, 



PLATE 23 

Hermanites cracens sp. nov. 
Left, right and dorsal views, carapace, x 70. Holotype, Io. 4336. 
Rakhi Nala. 



Gorge Beds, 



Hermanites scopus sp. nov. 

Figs. 4-7. Left, dorsal, ventral and right views, carapace male, x 70. 
Upper Chocolate Clays (lower part), sample 24148, Zao River. 

Figs. 8-10. Right, dorsal and ventral views, carapace female, x 70. 
Lower Chocolate Clays, sample 3499, Rakhi Nala. 



Holotype, Io. 4338. 
Paratype, Io. 4285. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. g 



PLATE 23 




PLATE 24 

Hermanites palmatus sp. nov. 

Figs, i, 2, 5. Dorsal, ventral and left views, carapace male, x 70. Paratype, Io. 4286. 
Upper Chocolate Clays (lower part), sample 24156, Zao River. 

Figs. 3, 4, 7. Dorsal, ventral and right views, carapace female, x 70. Paratype, Io. 31 17. 
Upper Chocolate Clays (lower part), sample 24156, Zao River. 

Figs. 6, 8, 9, 11. Dorsal, external, internal and ventral views, left valve female, x 70. 
Holotype, Io. 4337. Upper Chocolate Clays (lower part), sample 24152, Zao River. 

Fig. 12. External view, left valve female, x 70. Paratype, Io. 31 18. Upper Chocolate 
Clays (lower part), sample 3613, Rakhi Nala. 

Occultocythereis interrupta sp. nov. 

Figs. 10,13,15,16. Left, right, dorsal and ventral views, carapace male, x 116. Paratype, 
Io. 4287. Upper Palaeocene, sample 460-i, Sor Range, 8 miles east of Quetta. 

Figs. 14, 17, 18. Right, dorsal and ventral views, carapace female, x 116. Holotype, 
Io. 4339. Upper Palaeocene, sample 460-i, Sor Range, 8 miles east of Quetta. 



Bull. By. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 24 




PLATE 25 

Occultocythereis sp.A 
Figs. 1, 2, 5. Left, right and ventral views, carapace, x 116. Io. 3136. Lower Rakhi Gaj 
Shales, sample 3672, Rakhi Nala. 

Occultocythereis spilota sp. nov. 

Figs. 3, 4, 8, 9. Left, right, dorsal and ventral views, carapace male, x 120. Paratype, 
Io. 4288. Green and Nodular Shales, sample 3177, Rakhi Nala. 

Figs. 6,7,10,11. Left, right, dorsal and ventral views, carapace female, x 120. Holotype, 
Io. 4342. Green and Nodular Shales, sample 3177, Rakhi Nala. 

Occultocythereis peristicta sp. nov. 
Morphotype A 
Figs. 13, 14, 17. Left, right and ventral views, carapace male, x 118. Paratype, Io. 4292. 
Upper Rakhi Gaj Shales, sample 3167, Rakhi Nala. 

Figs. 15, 16. Left and right views, carapace female, x 118. Holotype, Io. 4341. Upper 
Rakhi Gaj Shales, sample 3167, Rakhi Nala. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. g 



PLATE 25 




PLATE 26 



Occultocythereis peristicta sp. nov. 

Morphotype A 
Fig. 1. Dorsal view, carapace male, x 118. Paratype, Io. 4292 

sample 3167, Rakhi Nala. 

Figs. 2,3. Dorsal and ventral views, carapace female, x 118. Holotype, Io. 4341 

Rakhi Gaj Shales, sample 3167, Rakhi Nala. 



Upper Rakhi Gaj Shales, 
Upper 



Morphotype B 

Figs. 4, 6, 7. Ventral, left and right views, carapace male, x 118. 
Green and Nodular Shales, sample 3193, Rakhi Nala. 

Figs. 5, 8, 9. Ventral, left and right views, carapace female, x 118. 
Green and Nodular Shales, sample 3193, Rakhi Nala. 



Paratype, Io. 4293. 
Paratype, Io. 4291. 



Morphotype C 

Figs. 10-12. Ventral, left and right views, carapace male, x 118. 
Green and Nodular Shales, sample 3 191, Rakhi Nala. 

Figs. 13-15. Left, right and ventral views, carapace female, x 118. 
Green and Nodular Shales, sample 3191, Rakhi Nala. 



Paratype, Io. 4289. 
Paratype, Io. 4290. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 26 




PLATE 



27 



Occultocythereis peristicta sp. nov. 
Morphotype D 
Figs, i, 2, 5. Left, right and ventral views, carapace male, x 
Green and Nodular Shales, sample 3 191, Rakhi Nala. 

Figs. 3, 4, 6. Left, right and ventral views, carapace female, x 
Green and Nodular Shales, sample 3 191, Rakhi Nala. 



118. Paratype, Io. 3146. 
118. Paratype, Io. 3139. 



Morphotype E 
Figs. 7, 9, 10. Ventral, right and left views, carapace male, x 118 

Rubbly Limestones, sample 3418, Rakhi Nala. 

Figs. 8, 11, 12. Ventral, left and right views, carapace female, x ni 

Rubbly Limestones, sample 3418, Rakhi Nala. 



Paratype, Io. 3137. 
Paratype, Io. 3138. 



Occultocythereis indistincta sp. nov. 

Figs. 13, 14. Ventral and right views, carapace male, x 120. Paratype, Io. 3135. Lower 
Chocolate Clays, sample 3499, Rakhi Nala. 

Fig. 15. Right view, carapace female, x 120. Holotype, Io. 4340. Lower Chocolate Clays, 
sample 3499, Rakhi Nala. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 27 




PLATE 28 

Occultocythereis indistincta sp. nov. 

Figs, i, 3, 4. Left, dorsal and ventral views, carapace female, x 120. Holotype, Io. 4340. 
Lower Chocolate Clays, sample 3499, Rakhi Nala. 

Fig. 2. Dorsal view, carapace male, x 120. Paratype, Io. 3135. Lower Chocolate Clays, 
sample 3499, Rakhi Nala. 

Patagonacy there ? nidulus sp. nov. 

Figs. 5-8. Left, right, dorsal and ventral views, carapace male, x 70. Paratype, Io. 3096. 
Upper Chocolate Clays (upper part), sample 24173, Zao River. 

Figs. 9-12. Left, right, dorsal and ventral views, carapace female, x 70. Holotype, Io. 4349 
Upper Chocolate Clays (lower part), sample 24173, Zao River. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. g 



PLATE 28 




PLATE 29 

Patagonacy there ? nidulus sp. nov. 

Specimens showing exaggerated normal pores after being cleaned in the 

ultrasonic vibrator. 

Figs. 1,2. 1, Internal view to show radial pore canals, x 160 ; 2, Dorsal view of hinge, 

X 150. Left valve female. Paratypes, Io. 3097. Upper Chocolate Clays (upper part), sample 

24170, Zao River. 

Fig. 3. Dorsal view of hinge, right valve female, X 150. Paratype, Io. 3098. Upper 
Chocolate Clays (upper part), sample 24170, Zao River. 

Fig. 4. Muscle scars X 260. Right valve male. Paratype, Io. 4295. Upper Chocolate 
Clays (upper part), sample 34170, Zao River. 

Phalcocythere horrescens (Bosquet) gen. nov. 
Fig. 5. Anterior radial pore canals, x 212. Left valve. Io. 4257. Lutetian IV (sample 
CAB 1002, Keij 1957, P- IQ )» Grignon, Paris Basin. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 29 




PLATE 30 

Phalcocythere horrescens (Bosquet) gen. nov. 

Figs, i, 2. External and internal views, left valve, x 68. Io. 4254. Lutetian IV (sample 
CAB 1002, Keij 1957, P- 1 9)> Grignon, Paris Basin. 

Figs. 3, 4. Dorsal and external views, left valve, x 68. Io. 4253. Lutetian IV (sample 
CAB 1002, Keij 1957, p. 19), Grignon, Paris Basin. 

Fig. 5. Muscle scars x 195. Right valve. Io. 4255. Lutetian IV (sample CAB 1002, 
Keij 1957, P- J 9). Grignon, Paris Basin. 

Fig. 6. Internal view, right valve, x 132. Io. 4256. Lutetian, Villiers-St. -Frederic, Paris 
Basin. 

Phalcocythere improcera sp. nov. 
(See PI. 33, figs. 12, 13 for hinge). 

Fig. 7. Anterior radial pore canals x 224. Left valve female. Paratype, Io. 4295. Upper 
Palaeocene, sample 460-i, Sor Range, 8 miles east of Quetta. 

Figs. 8, 9. Left and right views, carapace male, x 68. Holotype, Io. 4344. Upper 
Palaeocene, sample 460-i, Sor Range, 8 miles east of Quetta. 

Figs, io, ii. Left and right views, carapace female, X 68. Paratype, Io. 4258. Upper 
Palaeocene, sample 460-i, Sor Range, 8 miles east of Quetta. 

Fig. 12. Anterior radial pore canals x 224. Right valve female. Paratype, Io. 4296. 
Upper Palaeocene, sample 460-i, Sor Range, 8 miles east of Quetta. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 30 




PLATE 31 

Phalcocythere improcera sp. nov. 

Figs, i, 2. Dorsal and ventral views, carapace male, x 68. Holotype, Io. 4344. Upper 
Palaeocene, sample 460-i, Sor Range, 8 miles east of Quetta. 

Figs. 3, 4. Dorsal and ventral views, carapace female, x 68. Paratype, Io. 4258. Upper 
Palaeocene, sample 460-i, Sor Range, 8 miles east of Quetta. 

Phalcocythere rete sp. nov. 

Figs. 5-8. Left, right, dorsal and ventral views, carapace male, x 68. Paratype, Io. 3099. 
Upper Palaeocene, sample 460-i, Sor Range, 8 miles east of Quetta. 

Figs. 9-10. Dorsal and left views, carapace female, x 68. Paratype, Io. 4297. Upper 
Palaeocene, sample 460-i, Sor Range, 8 miles east of Quetta. 

Fig. ii. External view, right valve female, x 68. Holotype, Io. 4348. Upper Palaeocene, 
sample 460-i, Sor Range, 8 miles east of Quetta. 

Fig. 12. External view of valve female, x 68. Paratype, Io. 3141. L T pper Palaeocene, 
sample 460-i, Sor Range, 8 miles east of Quetta. 

Phalcocythere retispinata sp. nov. 

Figs. 13, 14, 17. Left, right and dorsal views, carapace male, x 68. Paratype, lo. 3165. 
Upper Palaeocene, sample 460-i, Sor Range, 8 miles east of Quetta. 

Figs. 15, 16. Left and right views, carapace female, x 68. Holotype, Io. 4345. Upper 
Palaeocene, sample 460-^ Sor Range, 8 miles east of Quetta. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. g 



PLATE 31 




PLATE 32 

Phalcocythere retispinata sp. nov. 

Fig. 1. Ventral view, carapace male, x 68. Paratype, Io. 3165. Upper Palaeocene, 
sample 460-i, Sor Range, 8 miles east of Quetta. 

Figs. 2, 3. Ventral and dorsal views, carapace female, x 68. Holotype, Io. 4345. Upper 
Palaeocene, sample 460-i, Sor Range, 8 miles east of Quetta. 

Phalcocythere sentosa sp. nov. 

Figs. 4, 5, 8, 10. Dorsal, left, right and ventral views, carapace male, x 68. Holotype, 
lo. 4346. Upper Rakhi Gaj Shales, sample 3167, Rakhi Nala. 

Figs. 6, 7, 9. Left, dorsal and right views, carapace female, x 68. Paratype, Io. 4298. 
Upper Rakhi Gaj Shales, sample 3167, Rakhi Nala. 

Phalcocythere dissenta sp. nov. 

Figs, ii, 13, 14, 18. Left, right, dorsal and ventral views, carapace male, x 68. Holotype, 
Io. 4343. Shales with Alabaster, sample 3456, Rakhi Nala. 

Figs. 12, 15-17. Left, right, dorsal and ventral views, carapace female, x 68. Paratype, 
Io. 4299. Shales with Alabaster, sample 3456, Rakhi Nala. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 32 




PLATE a 

Phalcocythere spinosa sp. nov. 
Figs, i, 2, 7, 8. Left, right, dorsal and ventral views, carapace, x 68. Holotype, Io. 4347. 
Fpper Chocolate Clays (upper part), sample 24161, Zao River. 

Phalcocythere sp., cf. P. spinosa 

Figs. 3,4,9. Left, right and ventral views, carapace male, x 68. Io. 4230. Upper Eocene, 
Lindi survey, 10-50 ft. above shore at Kitunga, Tanzania. 

Figs. 5, 6, 10. Left, right and dorsal views, carapace female, x 68. Io. 4231. Upper 
Eocene, Lindi survey, 10-50 ft. above shore at Kitunga, Tanzania. 

Fig. 11. Muscle scars x 210, fragment of right valve female. Io. 4232. Upper Eocene, 
Lindi survey, 10-50 ft. above shore at Kitunga, Tanzania. 

Phalcocythere horrescens (Bosquet) gen. nov. 

Fig. 12. Dorsal view of hinge x 183, left valve. Io. 4257. Lutetian IV (sample CAB 1002, 
Keij 1957, P- J 9)> Grignon, Paris Basin. 

Fig. 13. Dorsal view of hinge x 183, right valve. Io. 4255. Lutetian IV (sample CAB 
1002, Keij 1957, P- T 9)> Grignon, Paris Basin. 

Quadracythere (Hornibrookella) platybomus sp. nov. 

Figs. 14, 18. Right and dorsal view, carapace male, x 70. Holotype, Io. 4351. Upper 
Palaeocene, sample 460-i, Sor Range, 8 miles east of Quetta. 

Figs. 15, 19. Right and dorsal views, carapace female, x 70. Paratype, Io. 4300. Upper 
Palaeocene, sample 460-i, Sor Range, 8 miles east of Quetta. 

Quadracythere (Hornibrookella) directa sp. nov. 

Fig. 16. Left view, carapace male, x 70. Io. 4301. Green and Nodular Shales, sample 
3403, Rakhi Nala. 

Fig. 17. Left view, carapace female, x 70. Holotype, Io. 4350. Green and Nodular Shales, 
sample 3403, Rakhi Nala. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. g 



PLATE 33 




PLATE 34 

Quadracythere (Hornibrookella) directa sp. nov. 

Fig. i. Dorsal view, carapace male, x 70. Paratype, Io. 4301. Green and Nodular 
Shales, sample 3403, Rakhi Nala. 

Fig. 2. Dorsal view, carapace female, x 70. Holotype, Io. 4350. Green and Nodular 
Shales, sample 3403, Rakhi Nala. 

Quadracythere (Hornibrookella) arcana (Lubimova and Guha) 
Figs. 3-5. Right, left and dorsal views, carapace, x 70. Io. 3142. Lower Chocolate Clays, 
sample 3499, Rakhi Nala. 

Quadracythere (Hornibrookella) subquadra sp. now 

Figs. 6, 8, 9. Left, dorsal and ventral views, carapace male, x 70. Paratype, Io. 4302. 
Upper Chocolate Clays (upper part), sample 24161, Zao River. 

Figs. 7, 10, 11. Left, right and dorsal views, carapace female, x 70. Holotype, Io. 4352. 
Lpper Chocolate Clays (upper part), sample 24 161, Zao River. 

Quadracythere (Hornibrookella) sp.A 
Figs. 12-14. Left, right and dorsal views, carapace, x 70. Io. 3143. Upper Chocolate 
Clays (lower part), sample 24148, Zao River. 



Bull. Br. Mus. rial. Hist. (Geol.) Suppl. 9 



PLATE 34 




PLATE 35 

Stigmatocythere obliqua gen. et sp. nov. 

Fig. i. Dorsal view, carapace male, x 92. Specimen lost. Shales with Alabaster, sample 
24173, Rakhi Nala. 

Figs. 3, 4. Left and right views, carapace male, x 92. Paratype, Io. 4303. Shales with 
Alabaster, sample 24173, Rakhi Nala. 

Figs. 2, 5, 6. Dorsal, left and right views, carapace female, x 92. Holotype, Io. 4355. 
Shales with Alabaster, sample 24173, Rakhi Nala. 

Fig. 7. Dorsal view, left valve female, x 92. Paratype, Io. 3147. Shales with Alabaster, 
sample 24173, Rakhi Nala. 

Fig. 8. Dorsal view, right valve female, x 92. Paratype, Io. 3148. Shales with Alabaster, 
sample 24173, Rakhi Nala. 

Fig. 9. Internal view to show radial pore canals, right valve female, x 160. Paratype, 
Io. 3146. Shales with Alabaster, sample 24173, Rakhi Nala. 

Fig. 10. Internal view to show radial pore canals, left valve female, x 160. Paratype, 
Io. 3149. Shales with Alabaster, sample 24173, Rakhi Nala. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 35 




PLATE 36 

Stigmatocythere obliqua gen. et sp. nov. 

Fig. 1. Ventral view, carapace male, x 92. Paratype, Io. 4303. 
sample 24173, Rakhi Nala. 

Fig. 2. Ventral view, carapace male, X 92. Holotype, Io. 4355. 
sample 24173, Rakhi Nala. 



Shales with Alabaster, 
Shales with Alabaster, 



Stigmatocythere portentum sp. nov. 
Figs. 3-6. Dorsal, ventral, left and right views, carapace male, X 92. Holotype, Io. 4357. 
Lower Chocolate Clays, sample 3499, Rakhi Nala. 

Fig. 10. Anterior radial pore canals X 216, fragment of right valve. Paratype, Io. 3144. 



Stigmatocythere calia sp. nov. 

Fig. 7. External view, right valve male, x 92. Paratype, Io. 3404. Upper Chocolate 
Clays (lower part), sample 24152, Zao River. 

Figs. 8, 9. Right and dorsal views, carapace female, x 92. Holotvpe, Io. 4353. 1'pper 
Chocolate Clays (lower part), sample 24151, Zao River. 



Bull. Br. Mus. nat. His 


f. (Geol.) Suppl. g 






PLATE 36 






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PLATE 37 

Stigmatocythere calia sp. nov. 
Figs, i, 3. Left and ventral views, carapace female, x 92. Holotype, Io. 4353. Upper 
Chocolate Clays (lower part), sample 2415 1, Zao River. 

Stigmatocythere delineata sp. nov. 

Figs. 2, 4, 5, 6. Left dorsal, right and ventral views, carapace male, x 92. Paratype, 
Io. 4305. Upper Chocolate Clays (lower part), sample 24154, Zao River. 

Figs. 7-10. Dorsal, left, right and ventral views, carapace female, x 92. Holotype, Io. 4356. 
Upper Chocolate Clays (lower part), sample 24154, Zao River. 

Stigmatocythere lumaria sp. nov. 
Fig. 11. Anterior radial pore canals x 150, right valve female. Paratype, Io. 3154. Upper 
Chocolate Clays (upper part), sample 24174, Zao River. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 37 




PLATE 38 

Stigmatocy there lumaria sp. nov. 
Morphotype A 

Figs, i, 5, 6. Left, dorsal and ventral views, carapace male, x 92. Holotype, Io. 4354. 
Upper Chocolate Clays (upper part), sample 3642, Rakhi Nala. 

Figs. 2, 4, 7. External, internal and dorsal views, right valve male, x 92. Paratype, 
Io. 315 1. Upper Chocolate Clays (upper part), sample 3630, Rakhi Nala. 

Figs. 3,8. External and dorsal views, right valve female, x 92. Paratype, Io. 4307. Upper 
Chocolate Clays (upper part), sample 3630, Rakhi Nala. 

Fig. 9. Dorsal view of hinge x 240, left valve female. Paratype, Io. 3152. Upper Choco- 
late Clays (upper part), sample 24174, Zao River. 

Fig. 10. Dorsal view of hinge x 240, right valve female. Paratype, Io. 3154. Upper 
Chocolate Clays (upper part), sample 24174, Zao River. 



Bull. Br. Mas. uat. Hist. (Gc-ol.) Suppl. 9 



Mi 







PLATE 39 

Stigmatocy there lumaria sp. nov. 
Morphotype B 
Figs. 1-4. Left, right, dorsal and ventral views, carapace male, x 92. 
Upper Chocolate Clays (upper part), sample 3649, Rakhi Nala. 

Figs. 5-8. Left, dorsal, ventral and right views, carapace female, x 92. 
Upper Chocolate Clays (upper part), sample 3649, Rakhi Nala. 



Paratype, Io. 3150. 
Paratype, Io. 3153. 



Morphotype A 
Fig. 11. Anterior radial pore canals X 232, left valve male (juv.). Paratype, Io. 4306. 
Upper Chocolate Clays (upper part), sample 24174, Zao River. 



Trachyleberis (Trachyleberis) lobuculus sp. nov. 
Figs. 9, 10. Left and dorsal views, carapace male, x 94. Paratype, 
Rakhi Gaj Shales, sample 3163, Rakhi Nala. 



Io. 4308. Upper 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 39 




PLATE 40 

Trachyleberis (Trachyleberis) lobuculus sp. nov. 

Figs, i, 3. Left and dorsal views, carapace female, x 93. Holotype, Io. 43(34. Upper 
Rakhi Gaj Shales, sample 3166, Rakhi Nala. 

Trachyleberis (Trachyleberis) bimammillata sp. nov. 

Figs. 2, 8, 10. Left, right and dorsal views, carapace male, x 94. Holotype, Io. 4363. 
Upper Chocolate Clays (lower part), sample 3613, Rakhi Nala. 

Fig. 4. Dorsal view, left valve female, x 94. Paratype, Io. 3156. Upper Chocolate Clays 
(lower part), sample 361 1, Rakhi Nala. 

Fig. 5. Dorsal view, right valve female, x 94. Paratype, Io. 3155. Upper Chocolate 
Clays (lower part), sample 3614, Rakhi Nala. 

Fig. 6. Dorsal view, carapace male, x 94. Paratype, Io. 3160. Upper Chocolate Clays 
(lower part), sample 3613, Rakhi Nala. 

Fig. 7. Dorsal view, carapace female, x 94. Paratype, Io. 3157. Upper Chocolate Clays 
(lower part), sample 3613, Rakhi Nala. 

Fig. 9. Left view, carapace female, x 94. Paratype, Io. 3159. Upper Chocolate Clays 
(lower part) sample 3613, Rakhi Nala. 

Fig. 11. Muscle scars x 172, fragment of left valve male. Paratype, Io. 3158. Upper 
Chocolate Clays (lower part), sample 3613, Rakhi Nala. 

Trachyleberis (Acanthocythereis) procapsus sp. nov. 

Fig. 12. Left view, carapace male, x 94. Holotype, Io. 4360. Upper Palaeocene, sample 
460-i, Sor Range, 8 miles east of Quetta. 

Fig. 13. Left view, carapace female, x 94. Paratype, Io. 3164. Upper Palaeocene, sample 
460-j, Sor Range, 8 miles east of Quetta. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. g 



PLATE 40 




PLATE 41 

Trachyleberis (Acanthocythereis) procapsus sp. nov. 

Figs, i, 3. Right and dorsal views, carapace male, x 94. Holotype, Io. 4360. Upper 
Palaeocene, sample 460-i, Sor Range, 8 miles east of Quetta. 

Fig. 4. Dorsal view, carapace female, x 94. Paratype, Io. 3164. Upper Palaeocene, 
sample 460-j, Sor Range, 8 miles east of Quetta. 

Trachyleberis (Acanthocythereis) usitata sp. nov. 

Fig. 2. Right view, carapace male, x 94. Holotype, Io. 4362. Gorge Beds, sample 3111, 
Rakhi Nala. 

Figs. 5,7. Left and right views, carapace female, x 94. Paratype, Io. 3 161. Gorge Beds, 
sample 31 11, Rakhi Nala. 

Trachyleberis (Acanthocythereis) pedigaster sp. nov. 
Figs. 6, 8. Right and left views, carapace, x 70. Holotype, Io. 4358. Lower Rakhi Gaj 
Shales, sample 3671, Rakhi Nala. 

Trachyleberis (Acanthocythereis) postcornis sp. nov. 

Fig. 9. Left view, carapace male, x 94. Holotype, Io. 4361. Lower Chocolate Clays, 
sample 3499, Rakhi Nala. 

Fig. 10. Left view, carapace female, x 94. Paratype, Io. 3162. Lower Chocolate Clays, 
sample 3499, Rakhi Nala. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 9 



PLATE 41 




PLATE 42 
Trachyleberis (Acanthocythereis) postcornis sp. nov. 
Fig. 1. Dorsal view, carapace male, x 94. Holotype, Io. 4361. Lower Chocolate Clays, 
sample 3499, Rakhi Nala. 

Fig. 2. Dorsal view, carapace female, X 94. Paratype, Io. 3162. Lower Chocolate Clays, 
sample 3499, Rakhi Nala. 

Figs. 7, 10. 7, Dorsal view of hinge, x 232. 10, Internal view to show radial pore canals, 
x 178. Right valve female. Paratype, Io. 3163. Lower Chocolate Clays, sample ^498 
Rakhi Nala. ' 

Trachyleberis (Acanthocythereis) decoris sp. nov. 

lr|<;s - 3-5- Dorsal, left and right views, carapace male, \ 94. Holotype, Io. 4359. Upper 
Chocolate Clays (upper part), sample 3640, Rakhi Nala. 

Figs. 6, 8, 9. Dorsal, left and right views, carapace female, x 94. Paratype, Io. 4310. 
Upper Chocolate Clays (upper part), sample 3640, Rakhi Nala. 



Bull. Br. Mus. nat. Hist. (Geol.) Suppl. g 



PLATE 42 




1 Alocopocythere rupino sp no 

2 Buntonia devexa sp nov 

3 Hermanites cracens sp nov 

4 Trachyleberis (Acanthocythereis) usitata sp r 

5 Buntonia sp A. 

6 Occultocythereis sp. A 

7 Trachyleberis (Acanthocythercis) pedigaster sp r 

8 Alocopocythere abstracta sp nov 

9 Trachyleberis ( Trachyleberis) lobuculus sp. nov. 

10 Gyrocythere parvi carinata sp. nov. 

11 Phalcocythere sentosa sp. nov 

12 Occultocythereis peristicta sp nov morphotype A 

13 Alocopocythere transcendens sp.nov 
16 Occultocythereis spilota sp nov 

15 Occultocythereis peristicta sp nov morphotype B 

16 Ouadracythere (Hornibrookella) directa sp nov. 

17 Occultocythereis peristicta sp nov morphotype C 
15 Occultocythereis peristicta sp nov. morphotype D 

19 Occultocythereis peristicta sp nov morphotype E 

20 Anommatocythere laqueto sp nov. 

21 Echinocythereis ( Echinocythcreis) elongata sp. nov 

22 Alocopocythere coarctata sp.nov 

23 Alocopocythere longilinea sp nov 

24 Stigmatocythere obliqua sp nov. 

25 Gyrocythere grandilaevis sp nov 

26 Phalcocythere dissenta sp nov. 



G.B.i L.R.G.S 



10 3 20 1 11 9 1 2 6 13 20 25 18 37 6 17 20 10 2 1 1 30 20 42 2 16 18 7 7 5 - 50 10 45 70 70 B5 - 220250 40 55 30 55 100 35 32 38 30 18 190 22 42 5 3 33 55 40 10 170 68 55 30 75 205 55 45 40 90 175 - 19 



4 6 



- 4 2 - 2 3 2 - 1 1 5 - 19 1 14 1 - 2 3 1 14 5 2 18 15 15 9 33 - 
---14411 ------56- --1------23- 

2-8-3 16 W 72 11 1 - - 2 

- - 38 - - 26 14 - 1 3 - - 22 - 1 

1--------1 --32 10 -4 13 

1 1 - - 2 



26 11 7275-2272 
- 5 11 3 5 5 14 7 20 15 3 3 



10 



20 7 6 10 4344 5 26 3 4- 
10 1 



21 1 1 38 18 19 2 91 42 - 8 3 3 33 11 12 14 4 3 1 
------ 57 - - - - - - - - 7 31 

9--3115 412 1-------57--- 

22-11121--1------45--- 

3 11 - 5 1 1 17 2 3 2 1 3 - 



2 2 11 3 2 7 



8 8 3 14 7 10 1 23 2 13 
22 11 1 23 12 14 - - 3 - 



10 29 6 
12 7 



1 



39 1 
300 



23 



Upper Rakhi Gaj Shales 



Green and Nodular Shale 



_R_ubbly Li 



3 2 1 25145 22 - - 35 48 35 24 17023080.30 1 480 
10 4 1 1 
1 30 - - - 210135 50 - 70 
Shales with Alabaster 



G H A Z I 

J.0WER EOCENE 



Bull. Br. Mils. ml. Hist. (Geol.) Suppl. g 



Table 2. Stroti q raphic frequenc y of the ostracod family Trachyleberididae 
in the Middle and U p per Eocene of the Rakhi Nala , 



Samples with total no. of ostracods 






n w n n to co co <r> ro n o ro co co <*) n in " n n n n n n rocoronnoicoc^nnforococncncoron 



9 

10 
11 
12 
13 
14 
15 



Alocopocythere transcendens spnov. 

Gyrocythere perfecta sp. nov. 

Stigmatocy there portentum sp. nov. 

Trachyleberis (Acanthocythereis) postcornis sp. nov. 

Anommatocythere confirmata sp. nov. 

Echmocythereis ( Scelidocythereis) rasilis sp. nov. 

Hermanites scopus sp. nov. 

Occultocythereis indistincta sp nov. 

Quad racythere ( Hornibrookella) arcana (Lubimova & Guha) 

Costa (Paracosta) compitalis sp. nov. 

Trachyleberis (Acanthocythereis) decoris sp nov. 

Actinocythereis? quasibathonica sp. nov. 

Trachyleberis (Trachyleberis) bimammillata sp. nov. 

Gyrocythere exaggerata sp. nov. 

Hermanites palmatus sp. nov. 

16 Echinocythereis ( Scelidocythereis) multibullata sp. nov. 

17 Stigmatocythere lumaria sp. nov. morphotype A 

18 Costa (Paracosta) disintegrate sp.nov. 

19 Patagonacythere?nidulus sp.nov. 

20 Alocopocythere transversa sp. nov. morphotype A 

21 Alocopocythere transversa sp. nov. morphotype B 

22 Alocopocythere transversa sp. nov. morphotype C 

23 Alocopocythere transversa sp. nov morphotype D 

24 Alocopocythere transversa sp. nov. morphotype E 

25 Stigmatocythere lumaria sp.nov. morphotype B 

26 Alocopocythere transversa sp.nov morphotype F 

27 Alocopocythere radiata sp. nov. 

28 Costa (Paracosta) declivis sp. nov. 

W. M B = White Marl Bond 
LCC = Lower Chocolate Clays 
P l. = Platy Limestone 



If) 
Q 
O 
(_> 
< 
CC 
I— 

in 
o 



58 19 

5 15 

1 7 

12 33 

12 

12 

1 

2 

2 



- 2 1 



PL. i LCC. 



in 
a 
o 
o 
< 

r- 

o 



w 



-*|M 



1 



2 2 7 3 



- 3 6 17 32 

- - - 3 - 2 

4 - 4 1 1-2 

- --11 - --1 - - _ 7 ____ ___1 31 



14 

3 2 - 



8 2 



2 

13 



10 6 
5 2 
25 2 
7 1 
3 3 



- 1 



- 6 



6 5 



- 6 38 2 



- 51 6 9 10 



3 1 



1 1 1 



14 - 
2 - 
2 2 



13 1 

2 2 

14 5 

3 5 
3 



1 6 

- 5 

- 2 



6 5 1 13 6 1 23 42 38 6 - 



- 5 34 



5 - 



13 3 5 



- _ 5 - - 2 



3 14 3 
1 20 



2 - 



14 12 46 1 47 
- 8 30 - 35 2 
14 



Upper Chocolate Clays Lower part 



Upper Chocolate Clays upper part 



21 63 



7 19 6 2 
i Pellatispra Beds 



B LOWER KIR T H A R UKirthar sensu stricto of Eames ) 



UPPER KIRTHAR Mapti of Eamesl 



MIDDLE EOCENE 



UPPER EOCENE 



BM. Br. Mus. not. Hist. (Geol.) Suppl. g 



Table 3. Strati q raphic frequenc y of the ostracod family Trachyleberididae in the Eocene of the Zao River 




1 Anommatocythere laqueta sp nov. 

2 Phalcocythere dissenta sp nov. 

3 Stigmatocythere obliqua sp. nov. 
A Alocopocythere transcendens sp.nov. 

5 Gyrocythere mitigata sp. nov, 

6 Hermanites palmotus sp. nov. 

7 Trachyleberis (Acanthocy thereis)postcornis sp.nov. 
B Anommatocythere confirmata sp.nov 

9 Echinocythereis(Scelidocythereis) rasilis sp.nov. 

10 Gyrocythere exaggerata sp.nov. 

11 Hermanites scopus sp nov 

12 Ouadracythere ( Hornibrookella ) sp. A 

13 Stigmatocythere calia sp. nov, 

14 Actinocythereis 9 quasibathonica sp nov. 

15 Trachyleberis (Trachyleberis) bimammillata sp.nov. 

16 Patagonacythere?nidulus sp.nov. 

17 Echinocythereis (Scelidocythereis) multibullata sp.nov. 

18 Stigmatocythere delineata sp nov 

19 Trachylebens (Acanthocythereis) decoris sp nov. 

20 Alocopocythere transversa sp.nov. morphotype A. 

21 Alocopocythere transversa sp nov. morphotype B. 

22 Stigmatocythere lumaria sp.nov morphotype A 

23 Alocopocythere transversa sp. nov morphotype E 

24 Alocopocythere transversa sp. nov. morphotype C. 

25 Bradleya ? voraginosa sp.nov. 

26 Echinocythereis (Scelidocythereis) sparsa sp.nov. 

27 Phalcocythere spinosa sp. nov. 

28 Ouadracythere (Hornibrookella) subquadra sp.nov. 

29 Alocopocythere transversa sp. nov. morphotype D. 

30 Alocopocythere transversa sp.nov morphotype F 

31 Alocopocythere radiata sp.nov. 

W M. B. = White Marl Band 
L C.C. = Lower Chocolate Clays 
PL : Ploty Limestone 
SWA = Shales with Alabaster 



saaa 
VHidSiitmsd 



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31V10D0HD 



SAV1D 

31V10DOHO 

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Aiaana 

S31VHS 

anno>jsN33HCj^ 

S31WS 

rvo iH*va 
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S31VHS 
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Bull. Br. Mus. not. Hist. (Geo!.) Suppl. < 



Rakhi Nala Stratigraphic Section, 



ured by S.L.Rieb and sampled by D.D.Bayliss. 1957. 



— r 
s 8 



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GHAZIJ 






ABBREVIATIONS 




SCALE: Feet ond Melrei. 

0-5 inches ° 100 feel. 




Cov. Covered 




4-2 ant. = 100 meirei. 




S? Siwalik 












N.B. Sample numbers (or e 


ery fifth 


Pab sst. Pab Sondsto 


ne 


sompfe unless olherwise ind 


caled. 



H3- 



Sondilo 
Conglor 
-.1 Sill 






5illstone 

. | Siltstreoks 

Mudslone 



□ — 


= Shole or cloy 


L Z\ Mori 






Q' 



Shal 



Calcoreous 
'>r>' Gypsum 



— N ■*. 



"e 

I; 



■'I' :|Lli^o_ 



!f|i'f l| || 

%$M -I" S^ E l 
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B-P'E 

Sill 

illfl 



rto 



li III 

S»»ls 5 e g 1 s ." 



iK 



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=|° 

fe 

E-o- 

ill 
B&Jq 



n 



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J iiliitliiiylii 



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TFT 1 



\"~] ~ HUT 1 Kf pill lilF ■■ , Tt : 




(UD d j»ddn) SAV -| D 31V1030HD dSddD 



njDdjaMo-i) SAV -| 3 31V1030HD aaddn 



(Samoa io iidoi=) avHidix a3ddn 



3N3003 asddn 



S-W~D 31V1CO0H0 H3M01 



a315V8VW»"«3TW5l 



jjd 3 ( o opuis nsuas jomw«=) dVHldlVl d3M01 



3N3303 31QQIW 



S d „> 3N3X3 aawri 



o 






CD 


111 






XI 


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r 


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A LIST OF SUPPLEMENTS 

TO THE GEOLOGICAL SERIES 

OF THE BULLETIN OF 

THE BRITISH MUSEUM (NATURAL HISTORY) 



i. Cox, L. E. Jurassic Bivalvia and Gastropoda from Tanganyika and Kenya. 
Pp. 213; 30 Plates; 2 Text-figures. 1965. £6. 

2. El-Naggar, Z. R. Stratigraphy and Planktonic Foraminifera of the Upper 
Cretaceous — Lower Tertiary Succession in the Esna-Idfu Region, Nile Valley, 
Egypt, U.A.R. Pp. 291; 23 Plates; 18 Text-figures. 1966. £10. 

3. Davey, R. J., Downie, C, Sargeant, W. A. S. & Williams, G. L. Studies on 
Mesozoic and Cainozoic Dinoflagellate Cysts. Pp. 248; 28 Plates, 64 Text- 
figures. 1966. £y. 

3. Appendix. Davey, R. J., Downie, C, Sargeant, W. A. S. & Williams, G. L. 
Appendix to Studies on Mesozoic and Cainozoic Dinoflagellate Cysts. Pp. 24. 
1969. 16s. 

4. Elliott, G. F. Permian to Palaeocene Calcareous Algae (Dasycladaceae) of the 
Middle East. Pp. in; 24 Plates, 17 Text-figures. 1968. £5 2s. 6d. 

5. Rhodes, F. H. T., Austin, R. L. & Druce, E. C. British Avonian (Carboniferous) 
Conodont faunas, and their value in local and continental correlation. Pp. 315; 
31 Plates, 92 Text-figures. 1969. £11. 

6. Childs, A. Upper Jurassic Rhynchonellid Brachiopods from Northwestern 
Europe. Pp. 119; 12 Plates, 40 Text-figures. 1969. £4 15s. 

7. Goody, P. C. The relationships of certain Upper Cretaceous Teleosts with special 
reference to the Myctophoids Pp. 255 ; 102 Text-figures. 1969. £6 10s. 

8. Owen, H. G. Middle Albian Stratigraphy in the Anglo-Paris Basin. Pp. 164; 
3 Plates; 52 Text-figures. 1971. £6. 



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